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version 1.92, 2010/04/07 18:50:35 version 1.140, 2010/07/19 21:59:48
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 .\"     $Id$  .\"     $Id$
 .\"  .\"
 .\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>  .\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
   .\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
 .\"  .\"
 .\" Permission to use, copy, modify, and distribute this software for any  .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above  .\" purpose with or without fee is hereby granted, provided that the above
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 .Dd $Mdocdate$  .Dd $Mdocdate$
 .Dt MDOC 7  .Dt MDOC 7
 .Os  .Os
 .  
 .  
 .Sh NAME  .Sh NAME
 .Nm mdoc  .Nm mdoc
 .Nd mdoc language reference  .Nd mdoc language reference
 .  
 .  
 .Sh DESCRIPTION  .Sh DESCRIPTION
 The  The
 .Nm mdoc  .Nm mdoc
 language is used to format  language is used to format
 .Bx  .Bx
 .Ux  .Ux
 manuals.  In this reference document, we describe its syntax, structure,  manuals.
 and usage.  Our reference implementation is  In this reference document, we describe its syntax, structure, and
 .Xr mandoc 1 .  usage.
 The  Our reference implementation is mandoc; the
 .Sx COMPATIBILITY  .Sx COMPATIBILITY
 section describes compatibility with  section describes compatibility with other troff \-mdoc implementations.
 .Xr groff 1 .  
 .  
 .Pp  .Pp
 An  An
 .Nm  .Nm
 document follows simple rules:  lines beginning with the control  document follows simple rules: lines beginning with the control
 character  character
 .Sq \.  .Sq \.
 are parsed for macros.  Other lines are interpreted within the scope of  are parsed for macros.
   Other lines are interpreted within the scope of
 prior macros:  prior macros:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Sh Macro lines change control state.  \&.Sh Macro lines change control state.
 Other lines are interpreted within the current state.  Other lines are interpreted within the current state.
 .Ed  .Ed
 .  
 .  
 .Sh LANGUAGE SYNTAX  .Sh LANGUAGE SYNTAX
 .Nm  .Nm
 documents may contain only graphable 7-bit ASCII characters, the space  documents may contain only graphable 7-bit ASCII characters, the space
 character, and, in certain circumstances, the tab character.  All  character, and, in certain circumstances, the tab character.
 manuals must have  All manuals must have
 .Ux  .Ux
 line terminators.  line terminators.
 .  
 .  
 .Ss Comments  .Ss Comments
 Text following a  Text following a
 .Sq \e" ,  .Sq \e\*q ,
 whether in a macro or free-form text line, is ignored to the end of  whether in a macro or free-form text line, is ignored to the end of
 line.  A macro line with only a control character and comment escape,  line.
 .Sq \&.\e" ,  A macro line with only a control character and comment escape,
 is also ignored.  Macro lines with only a control charater and optionally  .Sq \&.\e\*q ,
 whitespace are stripped from input.  is also ignored.
 .  Macro lines with only a control character and optionally whitespace are
 .  stripped from input.
 .Ss Reserved Characters  .Ss Reserved Characters
 Within a macro line, the following characters are reserved:  Within a macro line, the following characters are reserved:
 .Pp  .Pp
Line 98  Within a macro line, the following characters are rese
Line 90  Within a macro line, the following characters are rese
 .It \&|  .It \&|
 .Pq vertical bar  .Pq vertical bar
 .El  .El
 .  
 .Pp  .Pp
 Use of reserved characters is described in  Use of reserved characters is described in
 .Sx MACRO SYNTAX .  .Sx MACRO SYNTAX .
Line 106  For general use in macro lines, these characters must 
Line 97  For general use in macro lines, these characters must 
 with a non-breaking space  with a non-breaking space
 .Pq Sq \e&  .Pq Sq \e&
 or, if applicable, an appropriate escape sequence used.  or, if applicable, an appropriate escape sequence used.
 .  
 .  
 .Ss Special Characters  .Ss Special Characters
 Special characters may occur in both macro and free-form lines.  Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character  Sequences begin with the escape character
Line 118  for two-character sequences; an open-bracket
Line 107  for two-character sequences; an open-bracket
 .Sq \&[  .Sq \&[
 for n-character sequences (terminated at a close-bracket  for n-character sequences (terminated at a close-bracket
 .Sq \&] ) ;  .Sq \&] ) ;
 or a single one-character sequence.  See  or a single one-character sequence.
   See
 .Xr mandoc_char 7  .Xr mandoc_char 7
 for a complete list.  Examples include  for a complete list.
   Examples include
 .Sq \e(em  .Sq \e(em
 .Pq em-dash  .Pq em-dash
 and  and
 .Sq \ee  .Sq \ee
 .Pq back-slash .  .Pq back-slash .
 .  
 .  
 .Ss Text Decoration  .Ss Text Decoration
 Terms may be text-decorated using the  Terms may be text-decorated using the
 .Sq \ef  .Sq \ef
Line 137  escape followed by an indicator: B (bold), I, (italic)
Line 126  escape followed by an indicator: B (bold), I, (italic)
 .D1 \efBbold\efR \efIitalic\efP  .D1 \efBbold\efR \efIitalic\efP
 .Pp  .Pp
 A numerical representation 3, 2, or 1 (bold, italic, and Roman,  A numerical representation 3, 2, or 1 (bold, italic, and Roman,
 respectively) may be used instead.  A text decoration is valid within  respectively) may be used instead.
 the current font scope only:  if a macro opens a font scope alongside  A text decoration is valid within
   the current font scope only: if a macro opens a font scope alongside
 its own scope, such as  its own scope, such as
 .Sx \&Bf  .Sx \&Bf
 .Cm \&Sy ,  .Cm \&Sy ,
 in-scope invocations of  in-scope invocations of
 .Sq \ef  .Sq \ef
 are only valid within the font scope of the macro.  If  are only valid within the font scope of the macro.
   If
 .Sq \ef  .Sq \ef
 is specified outside of any font scope, such as in unenclosed, free-form  is specified outside of any font scope, such as in unenclosed, free-form
 text, it will affect the remainder of the document.  text, it will affect the remainder of the document.
 .Pp  .Pp
 Text may also be sized with the  Note this form is
 .Sq \es  
 escape, whose syntax is one of  
 .Sq \es+-n  
 for one-digit numerals;  
 .Sq \es(+-nn  
 or  
 .Sq \es+-(nn  
 for two-digit numerals; and  
 .Sq \es[+-N] ,  
 .Sq \es+-[N] ,  
 .Sq \es'+-N' ,  
 or  
 .Sq \es+-'N'  
 for arbitrary-digit numerals:  
 .Pp  
 .D1 \es+1bigger\es-1  
 .D1 \es[+10]much bigger\es[-10]  
 .D1 \es+(10much bigger\es-(10  
 .D1 \es+'100'much much bigger\es-'100'  
 .Pp  
 Note these forms are  
 .Em not  .Em not
 recommended for  recommended for
 .Nm ,  .Nm ,
 which encourages semantic annotation.  which encourages semantic annotation.
 .  
 .  
 .Ss Predefined Strings  .Ss Predefined Strings
 Historically,  Historically,
 .Xr groff 1  .Xr groff 1
Line 184  also defined a set of package-specific
Line 152  also defined a set of package-specific
 .Dq predefined strings ,  .Dq predefined strings ,
 which, like  which, like
 .Sx Special Characters ,  .Sx Special Characters ,
 demark special output characters and strings by way of input codes.  mark special output characters and strings by way of input codes.
 Predefined strings are escaped with the slash-asterisk,  Predefined strings are escaped with the slash-asterisk,
 .Sq \e* :  .Sq \e* :
 single-character  single-character
Line 195  and N-character
Line 163  and N-character
 .Sq \e*[N] .  .Sq \e*[N] .
 See  See
 .Xr mandoc_char 7  .Xr mandoc_char 7
 for a complete list.  Examples include  for a complete list.
   Examples include
 .Sq \e*(Am  .Sq \e*(Am
 .Pq ampersand  .Pq ampersand
 and  and
 .Sq \e*(Ba  .Sq \e*(Ba
 .Pq vertical bar .  .Pq vertical bar .
 .  
 .  
 .Ss Whitespace  .Ss Whitespace
 In non-literal free-form lines, consecutive blocks of whitespace are  Whitespace consists of the space character.
 pruned from input and added later in the output filter, if applicable:  In free-form lines, whitespace is preserved within a line; un-escaped
 .Bd -literal -offset indent  trailing spaces are stripped from input (unless in a literal context).
 These     spaces   are    pruned       from    input.  Blank free-form lines, which may include whitespace, are only permitted
 \&.Bd \-literal  within literal contexts.
 These         are              not.  
 \&.Ed  
 .Ed  
 .  
 .Pp  .Pp
 In macro lines, whitespace delimits arguments and is discarded.  If  In macro lines, whitespace delimits arguments and is discarded.
 arguments are quoted, whitespace within the quotes is retained.  If arguments are quoted, whitespace within the quotes is retained.
 .  
 .Pp  
 Blank lines are only permitted within literal contexts, as are lines  
 containing only whitespace.  Tab characters are only acceptable when  
 delimiting  
 .Sq \&Bl \-column  
 or when in a literal context.  
 .  
 .  
 .Ss Quotation  .Ss Quotation
 Macro arguments may be quoted with a double-quote to group  Macro arguments may be quoted with a double-quote to group
 space-delimited terms or to retain blocks of whitespace.  A quoted  space-delimited terms or to retain blocks of whitespace.
 argument begins with a double-quote preceded by whitespace.  The next  A quoted argument begins with a double-quote preceded by whitespace.
 double-quote not pair-wise adjacent to another double-quote terminates  The next double-quote not pair-wise adjacent to another double-quote
 the literal, regardless of surrounding whitespace.  terminates the literal, regardless of surrounding whitespace.
 .  
 .Pp  .Pp
 This produces tokens  This produces tokens
 .Sq a" ,  .Sq a" ,
Line 240  This produces tokens
Line 193  This produces tokens
 and  and
 .Sq fg" .  .Sq fg" .
 Note that any quoted term, be it argument or macro, is indiscriminately  Note that any quoted term, be it argument or macro, is indiscriminately
 considered literal text.  Thus, the following produces  considered literal text.
   Thus, the following produces
 .Sq \&Em a :  .Sq \&Em a :
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Em "Em a"  \&.Em "Em a"
 .Ed  .Ed
 .  
 .Pp  .Pp
 In free-form mode, quotes are regarded as opaque text.  In free-form mode, quotes are regarded as opaque text.
 .  
 .Ss Dates  .Ss Dates
 There are several macros in  There are several macros in
 .Nm  .Nm
 that require a date argument.  The canonical form for dates is the  that require a date argument.
 American format:  The canonical form for dates is the American format:
 .Pp  .Pp
 .D1 Cm Month Day , Year  .D1 Cm Month Day , Year
 .Pp  .Pp
 The  The
 .Cm Day  .Cm Day
 value is an optionally zero-padded numeral.  The  value is an optionally zero-padded numeral.
   The
 .Cm Month  .Cm Month
 value is the full month name.  The  value is the full month name.
   The
 .Cm Year  .Cm Year
 value is the full four-digit year.  value is the full four-digit year.
 .Pp  .Pp
Line 275  Some examples of valid dates follow:
Line 229  Some examples of valid dates follow:
 .D1 "May, 2009" Pq reduced form  .D1 "May, 2009" Pq reduced form
 .D1 "2009" Pq reduced form  .D1 "2009" Pq reduced form
 .D1 "May 20, 2009" Pq canonical form  .D1 "May 20, 2009" Pq canonical form
 .  
 .Ss Scaling Widths  .Ss Scaling Widths
 Many macros support scaled widths for their arguments, such as  Many macros support scaled widths for their arguments, such as
 stipulating a two-inch list indentation with the following:  stipulating a two-inch list indentation with the following:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Bl -tag -width 2i  \&.Bl -tag -width 2i
 .Ed  .Ed
 .  
 .Pp  .Pp
 The syntax for scaled widths is  The syntax for scaled widths is
 .Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,  .Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
 where a decimal must be preceded or proceeded by at least one digit.  where a decimal must be preceded or proceeded by at least one digit.
 Negative numbers, while accepted, are truncated to zero.  The following  Negative numbers, while accepted, are truncated to zero.
 scaling units are accepted:  The following scaling units are accepted:
 .Pp  .Pp
 .Bl -tag -width Ds -offset indent -compact  .Bl -tag -width Ds -offset indent -compact
 .It c  .It c
Line 326  Using anything other than
Line 278  Using anything other than
 .Sq u ,  .Sq u ,
 or  or
 .Sq v  .Sq v
 is necessarily non-portable across output media.  See  is necessarily non-portable across output media.
   See
 .Sx COMPATIBILITY .  .Sx COMPATIBILITY .
 .  .Ss Sentence Spacing
 .  When composing a manual, make sure that your sentences end at the end of
   a line.
   By doing so, front-ends will be able to apply the proper amount of
   spacing after the end of sentence (unescaped) period, exclamation mark,
   or question mark followed by zero or more non-sentence closing
   delimiters (
   .Ns Sq \&) ,
   .Sq \&] ,
   .Sq \&' ,
   .Sq \&" ) .
   .Pp
   The proper spacing is also intelligently preserved if a sentence ends at
   the boundary of a macro line, e.g.,
   .Pp
   .D1 \&Xr mandoc 1 \.
   .D1 \&Fl T \&Ns \&Cm ascii \.
 .Sh MANUAL STRUCTURE  .Sh MANUAL STRUCTURE
 A well-formed  A well-formed
 .Nm  .Nm
Line 350  must be the NAME section, consisting of at least one
Line 318  must be the NAME section, consisting of at least one
 followed by  followed by
 .Sx \&Nd .  .Sx \&Nd .
 .Pp  .Pp
 Following that, convention dictates specifying at least the SYNOPSIS and  Following that, convention dictates specifying at least the
 DESCRIPTION sections, although this varies between manual sections.  .Em SYNOPSIS
   and
   .Em DESCRIPTION
   sections, although this varies between manual sections.
 .Pp  .Pp
 The following is a well-formed skeleton  The following is a well-formed skeleton
 .Nm  .Nm
Line 360  file:
Line 331  file:
 \&.Dd $\&Mdocdate$  \&.Dd $\&Mdocdate$
 \&.Dt mdoc 7  \&.Dt mdoc 7
 \&.Os  \&.Os
 \&.  
 \&.Sh NAME  \&.Sh NAME
 \&.Nm foo  \&.Nm foo
 \&.Nd a description goes here  \&.Nd a description goes here
 \&.\e\*q The next is for sections 2 & 3 only.  \&.\e\*q The next is for sections 2, 3, & 9 only.
 \&.\e\*q .Sh LIBRARY  \&.\e\*q .Sh LIBRARY
 \&.  
 \&.Sh SYNOPSIS  \&.Sh SYNOPSIS
 \&.Nm foo  \&.Nm foo
 \&.Op Fl options  \&.Op Fl options
 \&.Ar  \&.Ar
 \&.  
 \&.Sh DESCRIPTION  \&.Sh DESCRIPTION
 The  The
 \&.Nm  \&.Nm
 utility processes files ...  utility processes files ...
 \&.\e\*q .Sh IMPLEMENTATION NOTES  \&.\e\*q .Sh IMPLEMENTATION NOTES
 \&.\e\*q The next is for sections 1 & 8 only.  
 \&.\e\*q .Sh EXIT STATUS  
 \&.\e\*q The next is for sections 2, 3, & 9 only.  \&.\e\*q The next is for sections 2, 3, & 9 only.
 \&.\e\*q .Sh RETURN VALUES  \&.\e\*q .Sh RETURN VALUES
 \&.\e\*q The next is for sections 1, 6, 7, & 8 only.  \&.\e\*q The next is for sections 1, 6, 7, & 8 only.
 \&.\e\*q .Sh ENVIRONMENT  \&.\e\*q .Sh ENVIRONMENT
 \&.\e\*q .Sh FILES  \&.\e\*q .Sh FILES
   \&.\e\*q The next is for sections 1 & 8 only.
   \&.\e\*q .Sh EXIT STATUS
 \&.\e\*q .Sh EXAMPLES  \&.\e\*q .Sh EXAMPLES
 \&.\e\*q The next is for sections 1, 4, 6, 7, & 8 only.  \&.\e\*q The next is for sections 1, 4, 6, 7, & 8 only.
 \&.\e\*q .Sh DIAGNOSTICS  \&.\e\*q .Sh DIAGNOSTICS
Line 401  utility processes files ...
Line 369  utility processes files ...
 .Pp  .Pp
 The sections in a  The sections in a
 .Nm  .Nm
 document are conventionally ordered as they appear above.  Sections  document are conventionally ordered as they appear above.
 should be composed as follows:  Sections should be composed as follows:
 .Bl -ohang -offset Ds  .Bl -ohang -offset Ds
 .It Em NAME  .It Em NAME
 The name(s) and a short description of the documented material.  The  The name(s) and a short description of the documented material.
 syntax for this as follows:  The syntax for this as follows:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Nm name0  \&.Nm name0
 \&.Nm name1  \&.Nm name1
Line 424  See
Line 392  See
 .Sx \&Nm  .Sx \&Nm
 and  and
 .Sx \&Nd .  .Sx \&Nd .
 .  
 .It Em LIBRARY  .It Em LIBRARY
 The name of the library containing the documented material, which is  The name of the library containing the documented material, which is
 assumed to be a function in a section 2 or 3 manual.  The syntax for  assumed to be a function in a section 2, 3, or 9 manual.
 this is as follows:  The syntax for this is as follows:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Lb libarm  \&.Lb libarm
 .Ed  .Ed
 .Pp  .Pp
 See  See
 .Sx \&Lb .  .Sx \&Lb .
 .  
 .It Em SYNOPSIS  .It Em SYNOPSIS
 Documents the utility invocation syntax, function call syntax, or device  Documents the utility invocation syntax, function call syntax, or device
 configuration.  configuration.
Line 472  And for the third, configurations (section 4):
Line 438  And for the third, configurations (section 4):
 Manuals not in these sections generally don't need a  Manuals not in these sections generally don't need a
 .Em SYNOPSIS .  .Em SYNOPSIS .
 .Pp  .Pp
 See  Some macros are displayed differently in the
 .Sx \&Op ,  .Em SYNOPSIS
   section, particularly
   .Sx \&Nm ,
 .Sx \&Cd ,  .Sx \&Cd ,
   .Sx \&Fd ,
 .Sx \&Fn ,  .Sx \&Fn ,
 .Sx \&Ft ,  .Sx \&Fo ,
   .Sx \&In ,
   .Sx \&Vt ,
 and  and
 .Sx \&Vt .  .Sx \&Ft .
 .  All of these macros are output on their own line.
   If two such dissimilar macros are pair-wise invoked (except for
   .Sx \&Ft
   before
   .Sx \&Fo
   or
   .Sx \&Fn ) ,
   they are separated by a vertical space, unless in the case of
   .Sx \&Fo ,
   .Sx \&Fn ,
   and
   .Sx \&Ft ,
   which are always separated by vertical space.
   .Pp
   When text and macros following an
   .Sx \&Nm
   macro starting an input line span multiple output lines,
   all output lines but the first will be indented to align
   with the text immediately following the
   .Sx \&Nm
   macro, up to the next
   .Sx \&Nm ,
   .Sx \&Sx ,
   or
   .Sx \&Ss
   macro or the end of an enclosing block, whichever comes first.
 .It Em DESCRIPTION  .It Em DESCRIPTION
 This expands upon the brief, one-line description in  This expands upon the brief, one-line description in
 .Em NAME .  .Em NAME .
Line 494  Print verbose information.
Line 490  Print verbose information.
 .Ed  .Ed
 .Pp  .Pp
 Manuals not documenting a command won't include the above fragment.  Manuals not documenting a command won't include the above fragment.
 .  
 .It Em IMPLEMENTATION NOTES  .It Em IMPLEMENTATION NOTES
 Implementation-specific notes should be kept here.  This is useful when  Implementation-specific notes should be kept here.
 implementing standard functions that may have side effects or notable  This is useful when implementing standard functions that may have side
 algorithmic implications.  effects or notable algorithmic implications.
 .  
 .It Em EXIT STATUS  
 Command exit status for section 1, 6, and 8 manuals.  This section is  
 the dual of  
 .Em RETURN VALUES ,  
 which is used for functions.  Historically, this information was  
 described in  
 .Em DIAGNOSTICS ,  
 a practise that is now discouraged.  
 .Pp  
 See  
 .Sx \&Ex .  
 .  
 .It Em RETURN VALUES  .It Em RETURN VALUES
 This section is the dual of  This section is the dual of
 .Em EXIT STATUS ,  .Em EXIT STATUS ,
 which is used for commands.  It documents the return values of functions  which is used for commands.
 in sections 2, 3, and 9.  It documents the return values of functions in sections 2, 3, and 9.
 .Pp  .Pp
 See  See
 .Sx \&Rv .  .Sx \&Rv .
 .  
 .It Em ENVIRONMENT  .It Em ENVIRONMENT
 Documents any usages of environment variables, e.g.,  Documents any usages of environment variables, e.g.,
 .Xr environ 7 .  .Xr environ 7 .
 .Pp  .Pp
 See  See
 .Sx \&Ev .  .Sx \&Ev .
 .  
 .It Em FILES  .It Em FILES
 Documents files used.  It's helpful to document both the file and a  Documents files used.
 short description of how the file is used (created, modified, etc.).  It's helpful to document both the file and a short description of how
   the file is used (created, modified, etc.).
 .Pp  .Pp
 See  See
 .Sx \&Pa .  .Sx \&Pa .
 .  .It Em EXIT STATUS
   Command exit status for section 1, 6, and 8 manuals.
   This section is the dual of
   .Em RETURN VALUES ,
   which is used for functions.
   Historically, this information was described in
   .Em DIAGNOSTICS ,
   a practise that is now discouraged.
   .Pp
   See
   .Sx \&Ex .
 .It Em EXAMPLES  .It Em EXAMPLES
 Example usages.  This often contains snippets of well-formed,  Example usages.
 well-tested invocations.  Make doubly sure that your examples work  This often contains snippets of well-formed, well-tested invocations.
 properly!  Make doubly sure that your examples work properly!
 .  
 .It Em DIAGNOSTICS  .It Em DIAGNOSTICS
 Documents error conditions.  This is most useful in section 4 manuals.  Documents error conditions.
   This is most useful in section 4 manuals.
 Historically, this section was used in place of  Historically, this section was used in place of
 .Em EXIT STATUS  .Em EXIT STATUS
 for manuals in sections 1, 6, and 8; however, this practise is  for manuals in sections 1, 6, and 8; however, this practise is
Line 550  discouraged.
Line 541  discouraged.
 See  See
 .Sx \&Bl  .Sx \&Bl
 .Fl diag .  .Fl diag .
 .  
 .It Em ERRORS  .It Em ERRORS
 Documents error handling in sections 2, 3, and 9.  Documents error handling in sections 2, 3, and 9.
 .Pp  .Pp
 See  See
 .Sx \&Er .  .Sx \&Er .
 .  
 .It Em SEE ALSO  .It Em SEE ALSO
 References other manuals with related topics.  This section should exist  References other manuals with related topics.
 for most manuals.  Cross-references should conventionally be ordered  This section should exist for most manuals.
 first by section, then alphabetically.  Cross-references should conventionally be ordered first by section, then
   alphabetically.
 .Pp  .Pp
 See  See
 .Sx \&Xr .  .Sx \&Xr .
 .  
 .It Em STANDARDS  .It Em STANDARDS
 References any standards implemented or used.  If not adhering to any  References any standards implemented or used.
 standards, the  If not adhering to any standards, the
 .Em HISTORY  .Em HISTORY
 section should be used instead.  section should be used instead.
 .Pp  .Pp
 See  See
 .Sx \&St .  .Sx \&St .
 .  
 .It Em HISTORY  .It Em HISTORY
 The history of any manual without a  The history of any manual without a
 .Em STANDARDS  .Em STANDARDS
 section should be described in this section.  section should be described in this section.
 .  
 .It Em AUTHORS  .It Em AUTHORS
 Credits to authors, if applicable, should appear in this section.  Credits to authors, if applicable, should appear in this section.
 Authors should generally be noted by both name and an e-mail address.  Authors should generally be noted by both name and an e-mail address.
 .Pp  .Pp
 See  See
 .Sx \&An .  .Sx \&An .
 .  
 .It Em CAVEATS  .It Em CAVEATS
 Explanations of common misuses and misunderstandings should be explained  Explanations of common misuses and misunderstandings should be explained
 in this section.  in this section.
 .  
 .It Em BUGS  .It Em BUGS
 Extant bugs should be described in this section.  Extant bugs should be described in this section.
 .  
 .It Em SECURITY CONSIDERATIONS  .It Em SECURITY CONSIDERATIONS
 Documents any security precautions that operators should consider.  Documents any security precautions that operators should consider.
 .  
 .El  .El
 .  
 .  
 .Sh MACRO SYNTAX  .Sh MACRO SYNTAX
 Macros are one to three three characters in length and begin with a  Macros are one to three three characters in length and begin with a
 control character ,  control character ,
 .Sq \&. ,  .Sq \&. ,
 at the beginning of the line.  An arbitrary amount of whitespace may  at the beginning of the line.
 sit between the control character and the macro name.  Thus, the  An arbitrary amount of whitespace may sit between the control character
 following are equivalent:  and the macro name.
   Thus, the following are equivalent:
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Pp  \&.Pp
 \&.\ \ \ \&Pp  \&.\ \ \ \&Pp
 .Ed  .Ed
 .  
 .Pp  .Pp
 The syntax of a macro depends on its classification.  In this section,  The syntax of a macro depends on its classification.
   In this section,
 .Sq \-arg  .Sq \-arg
 refers to macro arguments, which may be followed by zero or more  refers to macro arguments, which may be followed by zero or more
 .Sq parm  .Sq parm
Line 621  parameters;
Line 603  parameters;
 opens the scope of a macro; and if specified,  opens the scope of a macro; and if specified,
 .Sq \&Yc  .Sq \&Yc
 closes it out.  closes it out.
 .  
 .Pp  .Pp
 The  The
 .Em Callable  .Em Callable
 column indicates that the macro may be called subsequent to the initial  column indicates that the macro may be called subsequent to the initial
 line-macro.  If a macro is not callable, then its invocation after the  line-macro.
 initial line macro is interpreted as opaque text, such that  If a macro is not callable, then its invocation after the initial line
   macro is interpreted as opaque text, such that
 .Sq \&.Fl \&Sh  .Sq \&.Fl \&Sh
 produces  produces
 .Sq Fl \&Sh .  .Sq Fl \&Sh .
 .  
 .Pp  .Pp
 The  The
 .Em Parsable  .Em Parsable
 column indicates whether the macro may be followed by further  column indicates whether the macro may be followed by further
 (ostensibly callable) macros.  If a macro is not parsable, subsequent  (ostensibly callable) macros.
 macro invocations on the line will be interpreted as opaque text.  If a macro is not parsable, subsequent macro invocations on the line
 .  will be interpreted as opaque text.
 .Pp  .Pp
 The  The
 .Em Scope  .Em Scope
 column, if applicable, describes closure rules.  column, if applicable, describes closure rules.
 .  
 .  
 .Ss Block full-explicit  .Ss Block full-explicit
 Multi-line scope closed by an explicit closing macro.  All macros  Multi-line scope closed by an explicit closing macro.
 contains bodies; only  All macros contains bodies; only
 .Sx \&Bf  .Sx \&Bf
 contains a head.  contains a head.
 .Bd -literal -offset indent  .Bd -literal -offset indent
Line 655  contains a head.
Line 634  contains a head.
 \(lBbody...\(rB  \(lBbody...\(rB
 \&.Yc  \&.Yc
 .Ed  .Ed
 .  
 .Pp  .Pp
 .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"  .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
Line 668  contains a head.
Line 646  contains a head.
 .It Sx \&Ek  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bk  .It Sx \&Ek  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bk
 .It Sx \&El  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bl  .It Sx \&El  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bl
 .El  .El
 .  
 .  
 .Ss Block full-implicit  .Ss Block full-implicit
 Multi-line scope closed by end-of-file or implicitly by another macro.  Multi-line scope closed by end-of-file or implicitly by another macro.
 All macros have bodies; some  All macros have bodies; some
Line 689  has multiple heads.
Line 665  has multiple heads.
 \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead... \(lBTa head...\(rB\(rB  \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead... \(lBTa head...\(rB\(rB
 \(lBbody...\(rB  \(lBbody...\(rB
 .Ed  .Ed
 .  
 .Pp  .Pp
 .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"  .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
 .It Sx \&It  Ta    \&No     Ta    Yes      Ta    closed by Sx \&It , Sx \&El  .It Sx \&It  Ta    \&No     Ta    Yes      Ta    closed by Sx \&It , Sx \&El
 .It Sx \&Nd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh  .It Sx \&Nd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh
   .It Sx \&Nm  Ta    \&No     Ta  Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss
 .It Sx \&Sh  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh  .It Sx \&Sh  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh
 .It Sx \&Ss  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh , Sx \&Ss  .It Sx \&Ss  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh , Sx \&Ss
 .El  .El
 .  .Pp
 .  Note that the
   .Sx \&Nm
   macro is a
   .Sx Block full-implicit
   macro only when invoked as the first macro
   in a
   .Em SYNOPSIS
   section line, else it is
   .Sx In-line .
 .Ss Block partial-explicit  .Ss Block partial-explicit
 Like block full-explicit, but also with single-line scope.  Each  Like block full-explicit, but also with single-line scope.
 has at least a body and, in limited circumstances, a head  Each has at least a body and, in limited circumstances, a head
 .Po  .Po
 .Sx \&Fo ,  .Sx \&Fo ,
 .Sx \&Eo  .Sx \&Eo
Line 717  and/or tail
Line 701  and/or tail
 \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB \  \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB \
 \(lBbody...\(rB \&Yc \(lBtail...\(rB  \(lBbody...\(rB \&Yc \(lBtail...\(rB
 .Ed  .Ed
 .  
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXXX" -compact -offset indent  .Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXXX" -compact -offset indent
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
Line 746  and/or tail
Line 729  and/or tail
 .It Sx \&Xc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Xo  .It Sx \&Xc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Xo
 .It Sx \&Xo  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Xc  .It Sx \&Xo  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Xc
 .El  .El
 .  
 .  
 .Ss Block partial-implicit  .Ss Block partial-implicit
 Like block full-implicit, but with single-line scope closed by  Like block full-implicit, but with single-line scope closed by
 .Sx Reserved Characters  .Sx Reserved Characters
Line 755  or end of line.
Line 736  or end of line.
 .Bd -literal -offset indent  .Bd -literal -offset indent
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB  \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
 .Ed  .Ed
 .  
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset indent  .Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset indent
 .It Em Macro Ta Em Callable Ta Em Parsable  .It Em Macro Ta Em Callable Ta Em Parsable
Line 778  Note that the
Line 758  Note that the
 macro is a  macro is a
 .Sx Block partial-implicit  .Sx Block partial-implicit
 only when invoked as the first macro  only when invoked as the first macro
 in a SYNOPSIS section line, else it is  in a
   .Em SYNOPSIS
   section line, else it is
 .Sx In-line .  .Sx In-line .
 .  
 .  
 .Ss In-line  .Ss In-line
 Closed by  Closed by
 .Sx Reserved Characters ,  .Sx Reserved Characters ,
 end of line, fixed argument lengths, and/or subsequent macros.  In-line  end of line, fixed argument lengths, and/or subsequent macros.
 macros have only text children.  If a number (or inequality) of  In-line macros have only text children.
 arguments is  If a number (or inequality) of arguments is
 .Pq n ,  .Pq n ,
 then the macro accepts an arbitrary number of arguments.  then the macro accepts an arbitrary number of arguments.
 .Bd -literal -offset indent  .Bd -literal -offset indent
Line 797  then the macro accepts an arbitrary number of argument
Line 777  then the macro accepts an arbitrary number of argument
   
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN  \&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
 .Ed  .Ed
 .  
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent  .Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments
Line 876  then the macro accepts an arbitrary number of argument
Line 855  then the macro accepts an arbitrary number of argument
 .It Sx \&br  Ta    \&No     Ta    \&No     Ta    0  .It Sx \&br  Ta    \&No     Ta    \&No     Ta    0
 .It Sx \&sp  Ta    \&No     Ta    \&No     Ta    1  .It Sx \&sp  Ta    \&No     Ta    \&No     Ta    1
 .El  .El
 .  
 .  
 .Sh REFERENCE  .Sh REFERENCE
 This section is a canonical reference of all macros, arranged  This section is a canonical reference of all macros, arranged
 alphabetically.  For the scoping of individual macros, see  alphabetically.
   For the scoping of individual macros, see
 .Sx MACRO SYNTAX .  .Sx MACRO SYNTAX .
 .  
 .Ss \&%A  .Ss \&%A
 Author name of an  Author name of an
 .Sx \&Rs  .Sx \&Rs
 block.  Multiple authors should each be accorded their own  block.
   Multiple authors should each be accorded their own
 .Sx \%%A  .Sx \%%A
 line.  Author names should be ordered with full or abbreviated  line.
 forename(s) first, then full surname.  Author names should be ordered with full or abbreviated forename(s)
 .  first, then full surname.
 .Ss \&%B  .Ss \&%B
 Book title of an  Book title of an
 .Sx \&Rs  .Sx \&Rs
 block.  This macro may also be used in a non-bibliographic context when  block.
   This macro may also be used in a non-bibliographic context when
 referring to book titles.  referring to book titles.
 .  
 .Ss \&%C  .Ss \&%C
 Publication city or location of an  Publication city or location of an
 .Sx \&Rs  .Sx \&Rs
Line 905  block.
Line 883  block.
 .Em Remarks :  .Em Remarks :
 this macro is not implemented in  this macro is not implemented in
 .Xr groff 1 .  .Xr groff 1 .
 .  
 .Ss \&%D  .Ss \&%D
 Publication date of an  Publication date of an
 .Sx \&Rs  .Sx \&Rs
 block.  This should follow the reduced or canonical form syntax  block.
 described in  This should follow the reduced or canonical form syntax described in
 .Sx Dates .  .Sx Dates .
 .  
 .Ss \&%I  .Ss \&%I
 Publisher or issuer name of an  Publisher or issuer name of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%J  .Ss \&%J
 Journal name of an  Journal name of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%N  .Ss \&%N
 Issue number (usually for journals) of an  Issue number (usually for journals) of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%O  .Ss \&%O
 Optional information of an  Optional information of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%P  .Ss \&%P
 Book or journal page number of an  Book or journal page number of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%Q  .Ss \&%Q
 Institutional author (school, government, etc.) of an  Institutional author (school, government, etc.) of an
 .Sx \&Rs  .Sx \&Rs
 block.  Multiple institutional authors should each be accorded their own  block.
   Multiple institutional authors should each be accorded their own
 .Sx \&%Q  .Sx \&%Q
 line.  line.
 .  
 .Ss \&%R  .Ss \&%R
 Technical report name of an  Technical report name of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&%T  .Ss \&%T
 Article title of an  Article title of an
 .Sx \&Rs  .Sx \&Rs
 block.  This macro may also be used in a non-bibliographical context  block.
 when referring to article titles.  This macro may also be used in a non-bibliographical context when
 .  referring to article titles.
 .Ss \&%U  .Ss \&%U
 URI of reference document.  URI of reference document.
 .  
 .Ss \&%V  .Ss \&%V
 Volume number of an  Volume number of an
 .Sx \&Rs  .Sx \&Rs
 block.  block.
 .  
 .Ss \&Ac  .Ss \&Ac
 Closes an  Closes an
 .Sx \&Ao  .Sx \&Ao
 block.  Does not have any tail arguments.  block.
 .  Does not have any tail arguments.
 .Ss \&Ad  .Ss \&Ad
 Address construct: usually in the context of an computational address in  Address construct: usually in the context of an computational address in
 memory, not a physical (post) address.  memory, not a physical (post) address.
Line 976  memory, not a physical (post) address.
Line 944  memory, not a physical (post) address.
 Examples:  Examples:
 .D1 \&.Ad [0,$]  .D1 \&.Ad [0,$]
 .D1 \&.Ad 0x00000000  .D1 \&.Ad 0x00000000
 .  
 .Ss \&An  .Ss \&An
 Author name.  This macro may alternatively accepts the following  Author name.
 arguments, although these may not be specified along with a parameter:  This macro may alternatively accepts the following arguments, although
 .Bl -tag -width 12n -offset indent  these may not be specified along with a parameter:
   .Pp
   .Bl -tag -width "-nosplitX" -offset indent -compact
 .It Fl split  .It Fl split
 Renders a line break before each author listing.  Renders a line break before each author listing.
 .It Fl nosplit  .It Fl nosplit
Line 988  The opposite of
Line 957  The opposite of
 .Fl split .  .Fl split .
 .El  .El
 .Pp  .Pp
 In the AUTHORS section, the default is not to split the first author  In the
   .Em AUTHORS
   section, the default is not to split the first author
 listing, but all subsequent author listings, whether or not they're  listing, but all subsequent author listings, whether or not they're
 interspersed by other macros or text, are split.  Thus, specifying  interspersed by other macros or text, are split.
   Thus, specifying
 .Fl split  .Fl split
 will cause the first listing also to be split.  If not in the AUTHORS  will cause the first listing also to be split.
   If not in the
   .Em AUTHORS
 section, the default is not to split.  section, the default is not to split.
 .Pp  .Pp
 Examples:  Examples:
Line 1004  the effects of
Line 978  the effects of
 .Fl split  .Fl split
 or  or
 .Fl nosplit  .Fl nosplit
 are re-set when entering the AUTHORS section, so if one specifies  are re-set when entering the
   .Em AUTHORS
   section, so if one specifies
 .Sx \&An Fl nosplit  .Sx \&An Fl nosplit
 in the general document body, it must be re-specified in the AUTHORS  in the general document body, it must be re-specified in the
   .Em AUTHORS
 section.  section.
 .  
 .Ss \&Ao  .Ss \&Ao
 Begins a block enclosed by angled brackets.  Does not have any head  Begins a block enclosed by angled brackets.
 arguments.  Does not have any head arguments.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac  .D1 \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
 .Pp  .Pp
 See also  See also
 .Sx \&Aq .  .Sx \&Aq .
 .  
 .Ss \&Ap  .Ss \&Ap
 Inserts an apostrophe without any surrounding white-space.  This is  Inserts an apostrophe without any surrounding whitespace.
 generally used as a grammatic device when referring to the verb form of  This is generally used as a grammatical device when referring to the verb
 a function:  form of a function.
 .Bd -literal -offset indent  .Pp
 \&.Fn execve Ap d  Examples:
 .Ed  .D1 \&.Fn execve \&Ap d
 .  
 .Ss \&Aq  .Ss \&Aq
 Encloses its arguments in angled brackets.  Encloses its arguments in angled brackets.
 .Pp  .Pp
Line 1045  statements, which should use
Line 1019  statements, which should use
 .Pp  .Pp
 See also  See also
 .Sx \&Ao .  .Sx \&Ao .
 .  
 .Ss \&Ar  .Ss \&Ar
 Command arguments.  If an argument is not provided, the string  Command arguments.
   If an argument is not provided, the string
 .Dq file ...  .Dq file ...
 is used as a default.  is used as a default.
 .Pp  .Pp
Line 1055  Examples:
Line 1029  Examples:
 .D1 \&.Fl o \&Ns \&Ar file1  .D1 \&.Fl o \&Ns \&Ar file1
 .D1 \&.Ar  .D1 \&.Ar
 .D1 \&.Ar arg1 , arg2 .  .D1 \&.Ar arg1 , arg2 .
 .  
 .Ss \&At  .Ss \&At
 Formats an AT&T version.  Accepts at most one parameter:  Formats an AT&T version.
 .Bl -tag -width 12n -offset indent  Accepts at most one parameter:
   .Pp
   .Bl -tag -width "v[1-7] | 32vX" -offset indent -compact
 .It Cm v[1-7] | 32v  .It Cm v[1-7] | 32v
 A version of  A version of
 .At .  .At .
Line 1082  See also
Line 1057  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Bc  .Ss \&Bc
 Closes a  Closes a
 .Sx \&Bo  .Sx \&Bo
 block.  Does not have any tail arguments.  block.
 .  Does not have any tail arguments.
 .Ss \&Bd  .Ss \&Bd
 Begins a display block.  A display is collection of macros or text which  Begins a display block.
 may be collectively offset or justified in a manner different from that  Its syntax is as follows:
 of the enclosing context.  By default, the block is preceded by a  .Bd -ragged -offset indent
 vertical space.  .Pf \. Sx \&Bd
   .Fl type
   .Op Fl offset Ar width
   .Op Fl compact
   .Ed
 .Pp  .Pp
   A display is collection of macros or text which may be collectively
   offset or justified in a manner different from that
   of the enclosing context.
   By default, the block is preceded by a vertical space.
   .Pp
 Each display is associated with a type, which must be one of the  Each display is associated with a type, which must be one of the
 following arguments:  following arguments:
 .Bl -tag -width 12n -offset indent  .Bl -tag -width 12n -offset indent
Line 1110  Alias for
Line 1093  Alias for
 Centre-justify each line.  Centre-justify each line.
 .El  .El
 .Pp  .Pp
 The type must be provided first.  Secondary arguments are as follows:  The type must be provided first.
   Secondary arguments are as follows:
 .Bl -tag -width 12n -offset indent  .Bl -tag -width 12n -offset indent
 .It Fl offset Ar width  .It Fl offset Ar val
 Offset by the value of  Offset by the value of
 .Ar width ,  .Ar val ,
 which is interpreted as one of the following, specified in order:  which is interpreted as one of the following, specified in order:
 .Bl -item  .Bl -item
 .It  .It
Line 1125  the width of standard indentation;
Line 1109  the width of standard indentation;
 twice  twice
 .Ar indent ;  .Ar indent ;
 .Ar left ,  .Ar left ,
 which has no effect ;  which has no effect;
 .Ar right ,  .Ar right ,
 which justifies to the right margin; and  which justifies to the right margin; and
 .Ar center ,  .Ar center ,
 which aligns around an imagined centre axis.  which aligns around an imagined centre axis.
 .It  .It
 As a precalculated width for a named macro.  The most popular is the  As a precalculated width for a named macro.
 imaginary macro  The most popular is the imaginary macro
 .Ar \&Ds ,  .Ar \&Ds ,
 which resolves to  which resolves to
 .Ar 6n .  .Ar 6n .
Line 1143  As a scaling unit following the syntax described in
Line 1127  As a scaling unit following the syntax described in
 As the calculated string length of the opaque string.  As the calculated string length of the opaque string.
 .El  .El
 .Pp  .Pp
 If unset, it will revert to the value of  If not provided an argument, it will be ignored.
 .Ar 8n  
 as described in  
 .Sx Scaling Widths .  
 .It Fl compact  .It Fl compact
 Do not assert a vertical space before the block.  Do not assert a vertical space before the block.
 .It Fl file Ar file  
 Prepend the file  
 .Ar file  
 before any text or macros within the block.  
 .El  .El
 .Pp  .Pp
 Examples:  Examples:
Line 1166  See also
Line 1143  See also
 .Sx \&D1  .Sx \&D1
 and  and
 .Sx \&Dl .  .Sx \&Dl .
 .  
 .Ss \&Bf  .Ss \&Bf
   Change the font mode for a scoped block of text.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Bf
   .Oo
   .Fl emphasis | literal | symbolic |
   .Cm \&Em | \&Li | \&Sy
   .Oc
   .Ed
   .Pp
   The
   .Fl emphasis
   and
   .Cm \&Em
   argument are equivalent, as are
   .Fl symbolic
   and
   .Cm \&Sy,
   and
   .Fl literal
   and
   .Cm \&Li .
   Without an argument, this macro does nothing.
   The font mode continues until broken by a new font mode in a nested
   scope or
   .Sx \&Ef
   is encountered.
   .Pp
   See also
   .Sx \&Li ,
   .Sx \&Ef ,
   and
   .Sx \&Sy .
 .Ss \&Bk  .Ss \&Bk
   Begins a collection of macros or text not breaking the line.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Bk Fl words
   .Pp
   Subsequent arguments are ignored.
   The
   .Fl words
   argument is required.
   .Pp
   Each line within a keep block is kept intact, so the following example
   will not break within each
   .Sx \&Op
   macro line:
   .Bd -literal -offset indent
   \&.Bk \-words
   \&.Op Fl f Ar flags
   \&.Op Fl o Ar output
   \&.Ek
   .Ed
   .Pp
   Be careful in using over-long lines within a keep block!
   Doing so will clobber the right margin.
 .Ss \&Bl  .Ss \&Bl
 .\" Begins a list composed of one or more list entries.  A list entry is  Begins a list composed of one or more list entries.
 .\" specified by the  Its syntax is as follows:
 .\" .Sx \&It  .Bd -ragged -offset indent
 .\" macro, which consists of a head and optional body.  By default, a list  .Pf \. Sx \&Bl
 .\" is preceded by a blank line.  A list must specify one of the following  .Fl type
 .\" list types:  .Op Fl width Ar val
 .\" .Bl -tag -width 12n  .Op Fl offset Ar val
 .\" .It Fl bullet  .Op Fl compact
 .\" A list offset by a bullet.  The head of list entries must be empty.  .Op HEAD ...
 .\" List entry bodies are justified after the bullet.  .Ed
 .\" .It Fl column  .Pp
 .\" A columnated list.  The number of columns is specified as arguments to  A list is associated with a type, which is a required argument.
 .\" the  Other arguments are
 .\" .Sx \&Bl  .Fl width ,
 .\" macro (the deprecated form of following the invocation of  defined per-type as accepting a literal or
 .\" .Fl column  .Sx Scaling Widths
 .\" is also accepted).  Arguments dictate the width of columns specified in  value;
 .\" list entries.  List entry bodies must be left empty.  Columns specified  .Fl offset ,
 .\" in the list entry head are justified to their position in the sequence  also accepting a literal or
 .\" of columns.  .Sx Scaling Widths
 .\" .It Fl dash  value setting the list's global offset; and
 .\" A list offset by a dash (hyphen).  The head of list entries must be  .Fl compact ,
 .\" empty.  List entry bodies are justified past the dash.  suppressing the default vertical space printed before each list entry.
 .\" .It Fl diag  A list entry is specified by the
 .\" Like  .Sx \&It
 .\" .Fl inset  macro, which consists of a head and optional body (depending on the list
 .\" lists, but with additional formatting to the head.  type).
 .\" .It Fl enum  A list must specify one of the following list types:
 .\" A list offset by a number indicating list entry position.  The head of  .Bl -tag -width 12n -offset indent
 .\" list entries must be empty.  List entry bodies are justified past the  .It Fl bullet
 .\" enumeration.  A list offset by a bullet.
 .\" .It Fl hang  The head of list entries must be empty.
 .\" Like  List entry bodies are positioned after the bullet.
 .\" .Fl tag ,  The
 .\" but instead of list bodies justifying to the head on the first line,  .Fl width
 .\" they trail the head text.  argument varies the width of list bodies' left-margins.
 .\" .It Fl hyphen  .It Fl column
 .\" Synonym for  A columnated list.
 .\" .Fl dash .  The
 .\" .It Fl inset  .Fl width
 .\" Like  argument has no effect.
 .\" .Fl tag ,  The number of columns is specified as parameters to the
 .\" but list entry bodies aren't justified.  .Sx \&Bl
 .\" .It Fl item  macro.
 .\" An un-justified list.  This produces blocks of text.  These dictate the width of columns either as
 .\" .It Fl ohang  .Sx Scaling Widths
 .\" List bodies are placed on the line following the head.  or literal text.
 .\" .It Fl tag  If the initial macro of a
 .\" A list offset by list entry heads.  List entry bodies are justified  .Fl column
 .\" after the head.  list is not an
 .\" .El  .Sx \&It ,
 .\" .Pp  an
 .\" More...  .Sx \&It
 .\" .  context spanning each line is implied until an
   .Sx \&It
   line macro is encountered, at which point list bodies are interpreted as
   described in the
   .Sx \&It
   documentation.
   .It Fl dash
   A list offset by a dash (hyphen).
   The head of list entries must be empty.
   List entry bodies are positioned past the dash.
   The
   .Fl width
   argument varies the width of list bodies' left-margins.
   .It Fl diag
   Like
   .Fl inset ,
   but with additional formatting to the head.
   The
   .Fl width
   argument varies the width of list bodies' left-margins.
   .It Fl enum
   An enumerated list offset by the enumeration from 1.
   The head of list entries must be empty.
   List entry bodies are positioned after the enumeration.
   The
   .Fl width
   argument varies the width of list bodies' left-margins.
   .It Fl hang
   Like
   .Fl tag ,
   but instead of list bodies positioned after the head, they trail the
   head text.
   The
   .Fl width
   argument varies the width of list bodies' left-margins.
   .It Fl hyphen
   Synonym for
   .Fl dash .
   .It Fl inset
   List bodies follow the list head.
   The
   .Fl width
   argument is ignored.
   .It Fl item
   This produces blocks of text.
   The head of list entries must be empty.
   The
   .Fl width
   argument is ignored.
   .It Fl ohang
   List bodies are positioned on the line following the head.
   The
   .Fl width
   argument is ignored.
   .It Fl tag
   A list offset by list entry heads.
   List entry bodies are positioned after the head as specified by the
   .Fl width
   argument.
   .El
   .Pp
   See also
   .Sx \&It .
 .Ss \&Bo  .Ss \&Bo
 Begins a block enclosed by square brackets.  Does not have any head  Begins a block enclosed by square brackets.
 arguments.  Does not have any head arguments.
 .Pp  .Pp
 Examples:  Examples:
 .Bd -literal -offset indent  .Bd -literal -offset indent -compact
 \&.Bo 1 ,  \&.Bo 1 ,
 \&.Dv BUFSIZ \&Bc  \&.Dv BUFSIZ \&Bc
 .Ed  .Ed
 .Pp  .Pp
 See also  See also
 .Sx \&Bq .  .Sx \&Bq .
 .  
 .Ss \&Bq  .Ss \&Bq
 Encloses its arguments in square brackets.  Encloses its arguments in square brackets.
 .Pp  .Pp
Line 1253  and
Line 1346  and
 .Pp  .Pp
 See also  See also
 .Sx \&Bo .  .Sx \&Bo .
 .  
 .Ss \&Brc  .Ss \&Brc
 Closes a  Closes a
 .Sx \&Bro  .Sx \&Bro
 block.  Does not have any tail arguments.  block.
 .  Does not have any tail arguments.
 .Ss \&Bro  .Ss \&Bro
 Begins a block enclosed by curly braces.  Does not have any head  Begins a block enclosed by curly braces.
 arguments.  Does not have any head arguments.
 .Pp  .Pp
 Examples:  Examples:
 .Bd -literal -offset indent  .Bd -literal -offset indent -compact
 \&.Bro 1 , ... ,  \&.Bro 1 , ... ,
 \&.Va n \&Brc  \&.Va n \&Brc
 .Ed  .Ed
 .Pp  .Pp
 See also  See also
 .Sx \&Brq .  .Sx \&Brq .
 .  
 .Ss \&Brq  .Ss \&Brq
 Encloses its arguments in curly braces.  Encloses its arguments in curly braces.
 .Pp  .Pp
Line 1280  Examples:
Line 1371  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Bro .  .Sx \&Bro .
 .  
 .Ss \&Bsx  .Ss \&Bsx
 Format the BSD/OS version provided as an argument, or a default value if  Format the BSD/OS version provided as an argument, or a default value if
 no argument is provided.  no argument is provided.
Line 1298  See also
Line 1388  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Bt  .Ss \&Bt
 Prints  Prints
 .Dq is currently in beta test.  .Dq is currently in beta test.
 .  
 .Ss \&Bx  .Ss \&Bx
 Format the BSD version provided as an argument, or a default value if no  Format the BSD version provided as an argument, or a default value if no
 argument is provided.  argument is provided.
Line 1320  See also
Line 1408  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Cd  .Ss \&Cd
 Configuration declaration (suggested for use in section four and nine  Configuration declaration.
 manuals).  This denotes strings accepted by  This denotes strings accepted by
 .Xr config 8 .  .Xr config 8 .
 .Pp  .Pp
 Examples:  Examples:
Line 1331  Examples:
Line 1418  Examples:
 .Pp  .Pp
 .Em Remarks :  .Em Remarks :
 this macro is commonly abused by using quoted literals to retain  this macro is commonly abused by using quoted literals to retain
 white-space and align consecutive  whitespace and align consecutive
 .Sx \&Cd  .Sx \&Cd
 declarations.  This practise is discouraged.  declarations.
 .  This practise is discouraged.
 .Ss \&Cm  .Ss \&Cm
 Command modifiers.  Useful when specifying configuration options or  Command modifiers.
 keys.  Useful when specifying configuration options or keys.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Cm ControlPath  .D1 \&.Cm ControlPath
Line 1345  Examples:
Line 1432  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Fl .  .Sx \&Fl .
 .  
 .Ss \&D1  .Ss \&D1
 One-line indented display.  This is formatted by the default rules and  One-line indented display.
 is useful for simple indented statements.  It is followed by a newline.  This is formatted by the default rules and is useful for simple indented
   statements.
   It is followed by a newline.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.D1 \&Fl abcdefgh  .D1 \&.D1 \&Fl abcdefgh
Line 1357  See also
Line 1445  See also
 .Sx \&Bd  .Sx \&Bd
 and  and
 .Sx \&Dl .  .Sx \&Dl .
 .  
 .Ss \&Db  .Ss \&Db
   Start a debugging context.
   This macro is parsed, but generally ignored.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Db Cm on | off
 .Ss \&Dc  .Ss \&Dc
 Closes a  Closes a
 .Sx \&Do  .Sx \&Do
 block.  Does not have any tail arguments.  block.
 .  Does not have any tail arguments.
 .Ss \&Dd  .Ss \&Dd
 Document date.  This is the mandatory first macro of any  Document date.
   This is the mandatory first macro of any
 .Nm  .Nm
 manual.  Its calling syntax is as follows:  manual.
   Its syntax is as follows:
 .Pp  .Pp
 .D1 \. Ns Sx \&Dd Cm date  .D1 Pf \. Sx \&Dd Cm date
 .Pp  .Pp
 The  The
 .Cm date  .Cm date
Line 1390  See also
Line 1484  See also
 .Sx \&Dt  .Sx \&Dt
 and  and
 .Sx \&Os .  .Sx \&Os .
 .  
 .Ss \&Dl  .Ss \&Dl
 One-line intended display.  This is formatted as literal text and is  One-line intended display.
 useful for commands and invocations.  It is followed by a newline.  This is formatted as literal text and is useful for commands and
   invocations.
   It is followed by a newline.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Dl % mandoc mdoc.7 | less  .D1 \&.Dl % mandoc mdoc.7 \e(ba less
 .Pp  .Pp
 See also  See also
 .Sx \&Bd  .Sx \&Bd
 and  and
 .Sx \&D1 .  .Sx \&D1 .
 .  
 .Ss \&Do  .Ss \&Do
 Begins a block enclosed by double quotes.  Does not have any head  Begins a block enclosed by double quotes.
 arguments.  Does not have any head arguments.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot  .Bd -literal -offset indent -compact
   \&.Do
   April is the cruellest month
   \&.Dc
   \e(em T.S. Eliot
   .Ed
 .Pp  .Pp
 See also  See also
 .Sx \&Dq .  .Sx \&Dq .
 .  
 .Ss \&Dq  .Ss \&Dq
 Encloses its arguments in double quotes.  Encloses its arguments in
   .Dq typographic
   double-quotes.
 .Pp  .Pp
 Examples:  Examples:
 .Bd -literal -offset indent -compact  .Bd -literal -offset indent -compact
Line 1423  Examples:
Line 1523  Examples:
 .Ed  .Ed
 .Pp  .Pp
 See also  See also
   .Sx \&Qq ,
   .Sx \&Sq ,
   and
 .Sx \&Do .  .Sx \&Do .
 .  
 .Ss \&Dt  .Ss \&Dt
 Document title.  This is the mandatory second macro of any  Document title.
   This is the mandatory second macro of any
 .Nm  .Nm
 file.  Its calling syntax is as follows:  file.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Dt
   .Oo
   .Cm title
   .Oo
   .Cm section
   .Op Cm volume | arch
   .Oc
   .Oc
   .Ed
 .Pp  .Pp
 .D1 \. Ns Sx \&Dt Cm title section Op Cm volume | arch  
 .Pp  
 Its arguments are as follows:  Its arguments are as follows:
 .Bl -tag -width Ds -offset Ds  .Bl -tag -width Ds -offset Ds
 .It Cm title  .It Cm title
 The document's title (name).  This should be capitalised and is  The document's title (name), defaulting to
 required.  .Dq UNKNOWN
   if unspecified.
   It should be capitalised.
 .It Cm section  .It Cm section
 The manual section.  This may be one of  The manual section.
   This may be one of
 .Ar 1  .Ar 1
 .Pq utilities ,  .Pq utilities ,
 .Ar 2  .Ar 2
Line 1472  The manual section.  This may be one of
Line 1587  The manual section.  This may be one of
 or  or
 .Ar paper  .Ar paper
 .Pq paper .  .Pq paper .
 It is also required and should correspond to the manual's filename  It should correspond to the manual's filename suffix and defaults to
 suffix.  .Dq 1
   if unspecified.
 .It Cm volume  .It Cm volume
 This overrides the volume inferred from  This overrides the volume inferred from
 .Ar section .  .Ar section .
Line 1504  or
Line 1620  or
 .Ar CON  .Ar CON
 .Pq contributed manuals .  .Pq contributed manuals .
 .It Cm arch  .It Cm arch
 This specifies a specific relevant architecture.  If  This specifies a specific relevant architecture.
   If
 .Cm volume  .Cm volume
 is not provided, it may be used in its place, else it may be used  is not provided, it may be used in its place, else it may be used
 subsequent that.  It, too, is optional.  It must be one of  subsequent that.
   It, too, is optional.
   It must be one of
 .Ar alpha ,  .Ar alpha ,
 .Ar amd64 ,  .Ar amd64 ,
 .Ar amiga ,  .Ar amiga ,
Line 1542  Examples:
Line 1661  Examples:
 .D1 \&.Dt FOO 1  .D1 \&.Dt FOO 1
 .D1 \&.Dt FOO 4 KM  .D1 \&.Dt FOO 4 KM
 .D1 \&.Dt FOO 9 i386  .D1 \&.Dt FOO 9 i386
 .D1 \&.Dt FOO 9 KM i386  
 .Pp  .Pp
 See also  See also
 .Sx \&Dd  .Sx \&Dd
 and  and
 .Sx \&Os .  .Sx \&Os .
 .  
 .Ss \&Dv  .Ss \&Dv
 Defined variables such as preprocessor constants.  Defined variables such as preprocessor constants.
 .Pp  .Pp
Line 1558  Examples:
Line 1675  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Er .  .Sx \&Er .
 .  
 .Ss \&Dx  .Ss \&Dx
 Format the DragonFly BSD version provided as an argument, or a default  Format the DragonFly BSD version provided as an argument, or a default
 value if no argument is provided.  value if no argument is provided.
Line 1576  See also
Line 1692  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Ec  .Ss \&Ec
   Close a scope started by
   .Sx \&Eo .
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Ec Op Cm TERM
   .Pp
   The
   .Cm TERM
   argument is used as the enclosure tail, for example, specifying \e(rq
   will emulate
   .Sx \&Dc .
 .Ss \&Ed  .Ss \&Ed
   End a display context started by
   .Sx \&Bd .
 .Ss \&Ef  .Ss \&Ef
   Ends a font mode context started by
   .Sx \&Bf .
 .Ss \&Ek  .Ss \&Ek
   Ends a keep context started by
   .Sx \&Bk .
 .Ss \&El  .Ss \&El
 .  Ends a list context started by
   .Sx \&Bl .
   .Pp
   See also
   .Sx \&Bl
   and
   .Sx \&It .
 .Ss \&Em  .Ss \&Em
 Denotes text that should be emphasised.  Note that this is a  Denotes text that should be emphasised.
 presentation term and should not be used for stylistically decorating  Note that this is a presentation term and should not be used for
 technical terms.  stylistically decorating technical terms.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Em Warnings!  .D1 \&.Em Warnings!
 .D1 \&.Em Remarks :  .D1 \&.Em Remarks :
 .  .Pp
   See also
   .Sx \&Bf ,
   .Sx \&Sy ,
   and
   .Sx \&Li .
 .Ss \&En  .Ss \&En
   This macro is obsolete and not implemented.
 .Ss \&Eo  .Ss \&Eo
   An arbitrary enclosure.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Eo Op Cm TERM
   .Pp
   The
   .Cm TERM
   argument is used as the enclosure head, for example, specifying \e(lq
   will emulate
   .Sx \&Do .
 .Ss \&Er  .Ss \&Er
 Display error constants.  Display error constants.
 .Pp  .Pp
Line 1603  Examples:
Line 1757  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Dv .  .Sx \&Dv .
 .  
 .Ss \&Es  .Ss \&Es
 .  This macro is obsolete and not implemented.
 .Ss \&Ev  .Ss \&Ev
 Environmental variables such as those specified in  Environmental variables such as those specified in
 .Xr environ 7 .  .Xr environ 7 .
Line 1613  Environmental variables such as those specified in
Line 1766  Environmental variables such as those specified in
 Examples:  Examples:
 .D1 \&.Ev DISPLAY  .D1 \&.Ev DISPLAY
 .D1 \&.Ev PATH  .D1 \&.Ev PATH
 .  
 .Ss \&Ex  .Ss \&Ex
 Inserts text regarding a utility's exit values.  This macro must have  Inserts text regarding a utility's exit value.
 first the  This macro must consist of the
 .Fl std  .Fl std
 argument specified, then an optional  argument followed by an optional
 .Ar utility .  .Ar utility .
 If  If
 .Ar utility  .Ar utility
 is not provided, the document's name as stipulated in  is not provided, the document's name as stipulated in
 .Sx \&Nm  .Sx \&Nm
 is provided.  is provided.
   .Pp
   See also
   .Sx \&Rv .
 .Ss \&Fa  .Ss \&Fa
   Function argument.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Fa
   .Op Cm argtype
   .Cm argname
   .Ed
   .Pp
   This may be invoked for names with or without the corresponding type.
   It is also used to specify the field name of a structure.
   Most often, the
   .Sx \&Fa
   macro is used in the
   .Em SYNOPSIS
   within
   .Sx \&Fo
   section when documenting multi-line function prototypes.
   If invoked with multiple arguments, the arguments are separated by a
   comma.
   Furthermore, if the following macro is another
   .Sx \&Fa ,
   the last argument will also have a trailing comma.
   .Pp
   Examples:
   .D1 \&.Fa \(dqconst char *p\(dq
   .D1 \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
   .D1 \&.Fa foo
   .Pp
   See also
   .Sx \&Fo .
 .Ss \&Fc  .Ss \&Fc
   Ends a function context started by
   .Sx \&Fo .
 .Ss \&Fd  .Ss \&Fd
   Historically used to document include files.
   This usage has been deprecated in favour of
   .Sx \&In .
   Do not use this macro.
   .Pp
   See also
   .Sx MANUAL STRUCTURE
   and
   .Sx \&In .
 .Ss \&Fl  .Ss \&Fl
 Command-line flag.  Used when listing arguments to command-line  Command-line flag.
 utilities.  Prints a fixed-width hyphen  Used when listing arguments to command-line utilities.
   Prints a fixed-width hyphen
 .Sq \-  .Sq \-
 directly followed by each argument.  If no arguments are provided, a hyphen is  directly followed by each argument.
 printed followed by a space.  If the argument is a macro, a hyphen is  If no arguments are provided, a hyphen is printed followed by a space.
 prefixed to the subsequent macro output.  If the argument is a macro, a hyphen is prefixed to the subsequent macro
   output.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Fl a b c  .D1 \&.Fl a b c
Line 1644  Examples:
Line 1842  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Cm .  .Sx \&Cm .
 .  
 .Ss \&Fn  .Ss \&Fn
   A function name.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Ns Sx \&Fn
   .Op Cm functype
   .Cm funcname
   .Op Oo Cm argtype Oc Cm argname
   .Ed
   .Pp
   Function arguments are surrounded in parenthesis and
   are delimited by commas.
   If no arguments are specified, blank parenthesis are output.
   .Pp
   Examples:
   .D1 \&.Fn "int funcname" "int arg0" "int arg1"
   .D1 \&.Fn funcname "int arg0"
   .D1 \&.Fn funcname arg0
   .Bd -literal -offset indent -compact
   \&.Ft functype
   \&.Fn funcname
   .Ed
   .Pp
   See also
   .Sx MANUAL STRUCTURE
   and
   .Sx \&Ft .
 .Ss \&Fo  .Ss \&Fo
 .Ss \&Fr  Begin a function block.
   This is a multi-line version of
   .Sx \&Fn .
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Fo Cm funcname
   .Pp
   Invocations usually occur in the following context:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Ft Cm functype
   .br
   .Pf \. Sx \&Fo Cm funcname
   .br
   .Pf \. Sx \&Fa Oo Cm argtype Oc Cm argname
   .br
   \.\.\.
   .br
   .Pf \. Sx \&Fc
   .Ed
   .Pp
   A
   .Sx \&Fo
   scope is closed by
   .Pp
   See also
   .Sx MANUAL STRUCTURE ,
   .Sx \&Fa ,
   .Sx \&Fc ,
   and
   .Sx \&Ft .
 .Ss \&Ft  .Ss \&Ft
   A function type.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Ft Cm functype
   .Pp
   Examples:
   .D1 \&.Ft int
   .Bd -literal -offset indent -compact
   \&.Ft functype
   \&.Fn funcname
   .Ed
   .Pp
   See also
   .Sx MANUAL STRUCTURE ,
   .Sx \&Fn ,
   and
   .Sx \&Fo .
 .Ss \&Fx  .Ss \&Fx
 Format the FreeBSD version provided as an argument, or a default value  Format the FreeBSD version provided as an argument, or a default value
 if no argument is provided.  if no argument is provided.
Line 1666  See also
Line 1935  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Hf  .Ss \&Hf
   This macro is obsolete and not implemented.
 .Ss \&Ic  .Ss \&Ic
   Designate an internal or interactive command.
   This is similar to
   .Sx \&Cm
   but used for instructions rather than values.
   .Pp
   Examples:
   .D1 \&.Ic hash
   .D1 \&.Ic alias
   .Pp
   Note that using
   .Sx \&Bd No Fl literal
   or
   .Sx \&D1
   is preferred for displaying code; the
   .Sx \&Ic
   macro is used when referring to specific instructions.
 .Ss \&In  .Ss \&In
   An
   .Dq include
   file.
   In the
   .Em SYNOPSIS
   section (only if invoked as the line macro), the first argument is
   preceded by
   .Dq #include ,
   the arguments is enclosed in angled braces.
   .Pp
   Examples:
   .D1 \&.In sys/types
   .Pp
   See also
   .Sx MANUAL STRUCTURE .
 .Ss \&It  .Ss \&It
   A list item.
   The syntax of this macro depends on the list type.
   .Pp
   Lists
   of type
   .Fl hang ,
   .Fl ohang ,
   .Fl inset ,
   and
   .Fl diag
   have the following syntax:
   .Pp
   .D1 Pf \. Sx \&It Cm args
   .Pp
   Lists of type
   .Fl bullet ,
   .Fl dash ,
   .Fl enum ,
   .Fl hyphen
   and
   .Fl item
   have the following syntax:
   .Pp
   .D1 Pf \. Sx \&It
   .Pp
   with subsequent lines interpreted within the scope of the
   .Sx \&It
   until either a closing
   .Sx \&El
   or another
   .Sx \&It .
   .Pp
   The
   .Fl tag
   list has the following syntax:
   .Pp
   .D1 Pf \. Sx \&It Op Cm args
   .Pp
   Subsequent lines are interpreted as with
   .Fl bullet
   and family.
   The line arguments correspond to the list's left-hand side; body
   arguments correspond to the list's contents.
   .Pp
   The
   .Fl column
   list is the most complicated.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&It Op Cm args
   .Pp
   The
   .Cm args
   are phrases, a mix of macros and text corresponding to a line column,
   delimited by tabs or the special
   .Sq \&Ta
   pseudo-macro.
   Lines subsequent the
   .Sx \&It
   are interpreted within the scope of the last phrase.
   Calling the pseudo-macro
   .Sq \&Ta
   will open a new phrase scope (this must occur on a macro line to be
   interpreted as a macro).
   Note that the tab phrase delimiter may only be used within the
   .Sx \&It
   line itself.
   Subsequent this, only the
   .Sq \&Ta
   pseudo-macro may be used to delimit phrases.
   Furthermore, note that quoted sections propagate over tab-delimited
   phrases on an
   .Sx \&It ,
   for example,
   .Pp
   .D1 .It \(dqcol1 ; <TAB> col2 ;\(dq \&;
   .Pp
   will preserve the semicolon whitespace except for the last.
   .Pp
   See also
   .Sx \&Bl .
 .Ss \&Lb  .Ss \&Lb
   Specify a library.
   The syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Lb Cm library
   .Pp
   The
   .Cm library
   parameter may be a system library, such as
   .Cm libz
   or
   .Cm libpam ,
   in which case a small library description is printed next to the linker
   invocation; or a custom library, in which case the library name is
   printed in quotes.
   This is most commonly used in the
   .Em SYNOPSIS
   section as described in
   .Sx MANUAL STRUCTURE .
   .Pp
   Examples:
   .D1 \&.Lb libz
   .D1 \&.Lb mdoc
 .Ss \&Li  .Ss \&Li
   Denotes text that should be in a literal font mode.
   Note that this is a presentation term and should not be used for
   stylistically decorating technical terms.
   .Pp
   See also
   .Sx \&Bf ,
   .Sx \&Sy ,
   and
   .Sx \&Em .
 .Ss \&Lk  .Ss \&Lk
 Format a hyperlink.  The calling syntax is as follows:  Format a hyperlink.
   Its syntax is as follows:
 .Pp  .Pp
 .D1 \. Ns Sx \&Lk Cm uri Op Cm name  .D1 Pf \. Sx \&Lk Cm uri Op Cm name
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Lk http://bsd.lv "The BSD.lv Project"  .D1 \&.Lk http://bsd.lv "The BSD.lv Project"
Line 1684  Examples:
Line 2097  Examples:
 .Pp  .Pp
 See also  See also
 .Sx \&Mt .  .Sx \&Mt .
 .  
 .Ss \&Lp  .Ss \&Lp
   Synonym for
   .Sx \&Pp .
 .Ss \&Ms  .Ss \&Ms
   Display a mathematical symbol.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Ms Cm symbol
   .Pp
   Examples:
   .D1 \&.Ms sigma
   .D1 \&.Ms aleph
 .Ss \&Mt  .Ss \&Mt
   Format a
   .Dq mailto:
   hyperlink.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Mt Cm address
   .Pp
   Examples:
   .D1 \&.Mt discuss@manpages.bsd.lv
 .Ss \&Nd  .Ss \&Nd
   A one-line description of the manual's content.
   This may only be invoked in the
   .Em SYNOPSIS
   section subsequent the
   .Sx \&Nm
   macro.
   .Pp
   Examples:
   .D1 \&.Sx \&Nd mdoc language reference
   .D1 \&.Sx \&Nd format and display UNIX manuals
   .Pp
   The
   .Sx \&Nd
   macro technically accepts child macros and terminates with a subsequent
   .Sx \&Sh
   invocation.
   Do not assume this behaviour: some
   .Xr whatis 1
   database generators are not smart enough to parse more than the line
   arguments and will display macros verbatim.
   .Pp
   See also
   .Sx \&Nm .
 .Ss \&Nm  .Ss \&Nm
   The name of the manual page, or \(em in particular in section 1, 6,
   and 8 pages \(em of an additional command or feature documented in
   the manual page.
   When first invoked, the
   .Sx \&Nm
   macro expects a single argument, the name of the manual page.
   Usually, the first invocation happens in the
   .Em NAME
   section of the page.
   The specified name will be remembered and used whenever the macro is
   called again without arguments later in the page.
   The
   .Sx \&Nm
   macro uses
   .Sx Block full-implicit
   semantics when invoked as the first macro on an input line in the
   .Em SYNOPSIS
   section; otherwise, it uses ordinary
   .Sx In-line
   semantics.
   .Pp
   Examples:
   .Bd -literal -offset indent
   \&.Sh SYNOPSIS
   \&.Nm cat
   \&.Op Fl benstuv
   \&.Op Ar
   .Ed
   .Pp
   In the
   .Em SYNOPSIS
   of section 2, 3 and 9 manual pages, use the
   .Sx \&Fn
   macro rather than
   .Sx \&Nm
   to mark up the name of the manual page.
 .Ss \&No  .Ss \&No
   A
   .Dq noop
   macro used to terminate prior macro contexts.
   .Pp
   Examples:
   .D1 \&.Sx \&Fl ab \&No cd \&Fl ef
 .Ss \&Ns  .Ss \&Ns
   Suppress a space.
   Following invocation, text is interpreted as free-form text until a
   macro is encountered.
   .Pp
   Examples:
   .D1 \&.Fl o \&Ns \&Ar output
   .Pp
   See also
   .Sx \&No
   and
   .Sx \&Sm .
 .Ss \&Nx  .Ss \&Nx
 Format the NetBSD version provided as an argument, or a default value if  Format the NetBSD version provided as an argument, or a default value if
 no argument is provided.  no argument is provided.
Line 1709  See also
Line 2216  See also
 .Sx \&Ox ,  .Sx \&Ox ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Oc  .Ss \&Oc
   Closes multi-line
   .Sx \&Oo
   context.
 .Ss \&Oo  .Ss \&Oo
   Multi-line version of
   .Sx \&Op .
   .Pp
   Examples:
   .Bd -literal -offset indent -compact
   \&.Oo
   \&.Op Fl flag Ns Ar value
   \&.Oc
   .Ed
 .Ss \&Op  .Ss \&Op
   Command-line option.
   Used when listing options to command-line utilities.
   Prints the argument(s) in brackets.
   .Pp
   Examples:
   .D1 \&.Op \&Fl a \&Ar b
   .D1 \&.Op \&Ar a | b
   .Pp
   See also
   .Sx \&Oo .
 .Ss \&Os  .Ss \&Os
 Document operating system version.  This is the mandatory third macro of  Document operating system version.
   This is the mandatory third macro of
 any  any
 .Nm  .Nm
 file.  Its calling syntax is as follows:  file.
   Its syntax is as follows:
 .Pp  .Pp
 .D1 \. Ns Sx \&Os Op Cm system  .D1 Pf \. Sx \&Os Op Cm system
 .Pp  .Pp
 The optional  The optional
 .Cm system  .Cm system
 parameter specifies the relevant operating system or environment.  Left  parameter specifies the relevant operating system or environment.
 unspecified, it defaults to the local operating system version.  This is  Left unspecified, it defaults to the local operating system version.
 the suggested form.  This is the suggested form.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Os  .D1 \&.Os
Line 1736  See also
Line 2266  See also
 .Sx \&Dd  .Sx \&Dd
 and  and
 .Sx \&Dt .  .Sx \&Dt .
 .  
 .Ss \&Ot  .Ss \&Ot
 Unknown usage.  Unknown usage.
 .Pp  .Pp
 .Em Remarks :  .Em Remarks :
 this macro has been deprecated.  this macro has been deprecated.
 .  
 .Ss \&Ox  .Ss \&Ox
 Format the OpenBSD version provided as an argument, or a default value  Format the OpenBSD version provided as an argument, or a default value
 if no argument is provided.  if no argument is provided.
Line 1760  See also
Line 2288  See also
 .Sx \&Nx ,  .Sx \&Nx ,
 and  and
 .Sx \&Ux .  .Sx \&Ux .
 .  
 .Ss \&Pa  .Ss \&Pa
   A file-system path.
   .Pp
   Examples:
   .D1 \&.Pa /usr/bin/mandoc
   .D1 \&.Pa /usr/share/man/man7/mdoc.7
   .Pp
   See also
   .Sx \&Lk .
 .Ss \&Pc  .Ss \&Pc
   Close parenthesised context opened by
   .Sx \&Po .
 .Ss \&Pf  .Ss \&Pf
   Removes the space
   .Pq Dq prefix
   between its arguments.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. \&Pf Cm prefix suffix
   .Pp
   The
   .Cm suffix
   argument may be a macro.
   .Pp
   Examples:
   .D1 \&.Pf \e. \&Sx \&Pf \&Cm prefix suffix
 .Ss \&Po  .Ss \&Po
   Multi-line version of
   .Sx \&Pq .
 .Ss \&Pp  .Ss \&Pp
   Break a paragraph.
   This will assert vertical space between prior and subsequent macros
   and/or text.
 .Ss \&Pq  .Ss \&Pq
   Parenthesised enclosure.
   .Pp
   See also
   .Sx \&Po .
 .Ss \&Qc  .Ss \&Qc
   Close quoted context opened by
   .Sx \&Qo .
 .Ss \&Ql  .Ss \&Ql
   Format a single-quoted literal.
   See also
   .Sx \&Qq
   and
   .Sx \&Sq .
 .Ss \&Qo  .Ss \&Qo
   Multi-line version of
   .Sx \&Qq .
 .Ss \&Qq  .Ss \&Qq
 .  Encloses its arguments in
   .Dq typewriter
   double-quotes.
   Consider using
   .Sx \&Dq .
   .Pp
   See also
   .Sx \&Dq ,
   .Sx \&Sq ,
   and
   .Sx \&Qo .
 .Ss \&Re  .Ss \&Re
 Closes a  Closes a
 .Sx \&Rs  .Sx \&Rs
 block.  Does not have any tail arguments.  block.
 .  Does not have any tail arguments.
 .Ss \&Rs  .Ss \&Rs
 Begins a bibliographic  Begins a bibliographic
 .Pq Dq reference  .Pq Dq reference
 block.  Does not have any head arguments.  The block macro may only  block.
 contain  Does not have any head arguments.
   The block macro may only contain
 .Sx \&%A ,  .Sx \&%A ,
 .Sx \&%B ,  .Sx \&%B ,
 .Sx \&%C ,  .Sx \&%C ,
Line 1794  contain
Line 2373  contain
 .Sx \&%Q ,  .Sx \&%Q ,
 .Sx \&%R ,  .Sx \&%R ,
 .Sx \&%T ,  .Sx \&%T ,
   .Sx \&%U ,
 and  and
 .Sx \&%V  .Sx \&%V
 child macros (at least one must be specified).  child macros (at least one must be specified).
Line 1815  If an
Line 2395  If an
 block is used within a SEE ALSO section, a vertical space is asserted  block is used within a SEE ALSO section, a vertical space is asserted
 before the rendered output, else the block continues on the current  before the rendered output, else the block continues on the current
 line.  line.
 .  
 .Ss \&Rv  .Ss \&Rv
   Inserts text regarding a function call's return value.
   This macro must consist of the
   .Fl std
   argument followed by an optional
   .Ar function .
   If
   .Ar function
   is not provided, the document's name as stipulated by the first
   .Sx \&Nm
   is provided.
   .Pp
   See also
   .Sx \&Ex .
 .Ss \&Sc  .Ss \&Sc
   Close single-quoted context opened by
   .Sx \&So .
 .Ss \&Sh  .Ss \&Sh
   Begin a new section.
   For a list of conventional manual sections, see
   .Sx MANUAL STRUCTURE .
   These sections should be used unless it's absolutely necessary that
   custom sections be used.
   .Pp
   Section names should be unique so that they may be keyed by
   .Sx \&Sx .
   .Pp
   See also
   .Sx \&Pp ,
   .Sx \&Ss ,
   and
   .Sx \&Sx .
 .Ss \&Sm  .Ss \&Sm
   Switches the spacing mode for output generated from macros.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Sm Cm on | off
   .Pp
   By default, spacing is
   .Cm on .
   When switched
   .Cm off ,
   no white space is inserted between macro arguments and between the
   output generated from adjacent macros, but free-form text lines
   still get normal spacing between words and sentences.
 .Ss \&So  .Ss \&So
   Multi-line version of
   .Sx \&Sq .
 .Ss \&Sq  .Ss \&Sq
   Encloses its arguments in
   .Dq typewriter
   single-quotes.
   .Pp
   See also
   .Sx \&Dq ,
   .Sx \&Qq ,
   and
   .Sx \&So .
 .Ss \&Ss  .Ss \&Ss
   Begin a new sub-section.
   Unlike with
   .Sx \&Sh ,
   there's no convention for sub-sections.
   Conventional sections, as described in
   .Sx MANUAL STRUCTURE ,
   rarely have sub-sections.
   .Pp
   Sub-section names should be unique so that they may be keyed by
   .Sx \&Sx .
   .Pp
   See also
   .Sx \&Pp ,
   .Sx \&Sh ,
   and
   .Sx \&Sx .
 .Ss \&St  .Ss \&St
   Replace an abbreviation for a standard with the full form.
   The following standards are recognised:
   .Pp
   .Bl -tag -width "-p1003.1g-2000X" -compact
   .It \-p1003.1-88
   .St -p1003.1-88
   .It \-p1003.1-90
   .St -p1003.1-90
   .It \-p1003.1-96
   .St -p1003.1-96
   .It \-p1003.1-2001
   .St -p1003.1-2001
   .It \-p1003.1-2004
   .St -p1003.1-2004
   .It \-p1003.1-2008
   .St -p1003.1-2008
   .It \-p1003.1
   .St -p1003.1
   .It \-p1003.1b
   .St -p1003.1b
   .It \-p1003.1b-93
   .St -p1003.1b-93
   .It \-p1003.1c-95
   .St -p1003.1c-95
   .It \-p1003.1g-2000
   .St -p1003.1g-2000
   .It \-p1003.1i-95
   .St -p1003.1i-95
   .It \-p1003.2-92
   .St -p1003.2-92
   .It \-p1003.2a-92
   .St -p1003.2a-92
   .It \-p1387.2-95
   .St -p1387.2-95
   .It \-p1003.2
   .St -p1003.2
   .It \-p1387.2
   .St -p1387.2
   .It \-isoC
   .St -isoC
   .It \-isoC-90
   .St -isoC-90
   .It \-isoC-amd1
   .St -isoC-amd1
   .It \-isoC-tcor1
   .St -isoC-tcor1
   .It \-isoC-tcor2
   .St -isoC-tcor2
   .It \-isoC-99
   .St -isoC-99
   .It \-iso9945-1-90
   .St -iso9945-1-90
   .It \-iso9945-1-96
   .St -iso9945-1-96
   .It \-iso9945-2-93
   .St -iso9945-2-93
   .It \-ansiC
   .St -ansiC
   .It \-ansiC-89
   .St -ansiC-89
   .It \-ansiC-99
   .St -ansiC-99
   .It \-ieee754
   .St -ieee754
   .It \-iso8802-3
   .St -iso8802-3
   .It \-ieee1275-94
   .St -ieee1275-94
   .It \-xpg3
   .St -xpg3
   .It \-xpg4
   .St -xpg4
   .It \-xpg4.2
   .St -xpg4.2
   .St -xpg4.3
   .It \-xbd5
   .St -xbd5
   .It \-xcu5
   .St -xcu5
   .It \-xsh5
   .St -xsh5
   .It \-xns5
   .St -xns5
   .It \-xns5.2
   .St -xns5.2
   .It \-xns5.2d2.0
   .St -xns5.2d2.0
   .It \-xcurses4.2
   .St -xcurses4.2
   .It \-susv2
   .St -susv2
   .It \-susv3
   .St -susv3
   .It \-svid4
   .St -svid4
   .El
 .Ss \&Sx  .Ss \&Sx
   Reference a section or sub-section.
   The referenced section or sub-section name must be identical to the
   enclosed argument, including whitespace.
   .Pp
   Examples:
   .D1 \&.Sx MANUAL STRUCTURE
 .Ss \&Sy  .Ss \&Sy
   Format enclosed arguments in symbolic
   .Pq Dq boldface .
   Note that this is a presentation term and should not be used for
   stylistically decorating technical terms.
   .Pp
   See also
   .Sx \&Bf ,
   .Sx \&Li ,
   and
   .Sx \&Em .
 .Ss \&Tn  .Ss \&Tn
   Format a tradename.
   .Pp
   Examples:
   .D1 \&.Tn IBM
 .Ss \&Ud  .Ss \&Ud
   Prints out
   .Dq currently under development.
 .Ss \&Ux  .Ss \&Ux
 Format the UNIX name.  Accepts no argument.  Format the UNIX name.
   Accepts no argument.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Ux  .D1 \&.Ux
Line 1843  See also
Line 2609  See also
 .Sx \&Nx ,  .Sx \&Nx ,
 and  and
 .Sx \&Ox .  .Sx \&Ox .
 .  
 .Ss \&Va  .Ss \&Va
   A variable name.
   .Pp
   Examples:
   .D1 \&.Va foo
   .D1 \&.Va const char *bar ;
 .Ss \&Vt  .Ss \&Vt
 A variable type.  This is also used for indicating global variables in the  A variable type.
 SYNOPSIS section, in which case a variable name is also specified.  Note that  This is also used for indicating global variables in the
 it accepts  .Em SYNOPSIS
   section, in which case a variable name is also specified.
   Note that it accepts
 .Sx Block partial-implicit  .Sx Block partial-implicit
 syntax when invoked as the first macro in the SYNOPSIS section, else it  syntax when invoked as the first macro in the
 accepts ordinary  .Em SYNOPSIS
   section, else it accepts ordinary
 .Sx In-line  .Sx In-line
 syntax.  syntax.
 .Pp  .Pp
Line 1861  which is used for function return types.
Line 2634  which is used for function return types.
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Vt unsigned char  .D1 \&.Vt unsigned char
 .D1 \&.Vt extern const char * const sys_signame[] ;  .D1 \&.Vt extern const char * const sys_signame[] \&;
 .Pp  .Pp
 See also  See also
 .Sx \&Ft  .Sx MANUAL STRUCTURE
 and  and
 .Sx \&Va .  .Sx \&Va .
 .  
 .Ss \&Xc  .Ss \&Xc
 Close a scope opened by  Close a scope opened by
 .Sx \&Xo .  .Sx \&Xo .
 .  
 .Ss \&Xo  .Ss \&Xo
 Open an extension scope.  This macro originally existed to extend the  Open an extension scope.
 9-argument limit of troff; since this limit has been lifted, the macro  This macro originally existed to extend the 9-argument limit of troff;
 has been deprecated.  since this limit has been lifted, the macro has been deprecated.
 .  
 .Ss \&Xr  .Ss \&Xr
 Link to another manual  Link to another manual
 .Pq Qq cross-reference .  .Pq Qq cross-reference .
 Its calling syntax is  Its syntax is as follows:
 .Pp  .Pp
 .D1 \. Ns Sx \&Xr Cm name section  .D1 Pf \. Sx \&Xr Cm name section
 .Pp  .Pp
 The  The
 .Cm name  .Cm name
 and  and
 .Cm section  .Cm section
 are the name and section of the linked manual.  If  are the name and section of the linked manual.
   If
 .Cm section  .Cm section
 is followed by non-punctuation, an  is followed by non-punctuation, an
 .Sx \&Ns  .Sx \&Ns
 is inserted into the token stream.  This behaviour is for compatibility  is inserted into the token stream.
 with  This behaviour is for compatibility with
 .Xr groff 1 .  .Xr groff 1 .
 .Pp  .Pp
 Examples:  Examples:
 .D1 \&.Xr mandoc 1  .D1 \&.Xr mandoc 1
 .D1 \&.Xr mandoc 1 ;  .D1 \&.Xr mandoc 1 \&;
 .D1 \&.Xr mandoc 1 \&Ns s behaviour  .D1 \&.Xr mandoc 1 \&Ns s behaviour
 .  
 .Ss \&br  .Ss \&br
   Emits a line-break.
   This macro should not be used; it is implemented for compatibility with
   historical manuals.
   .Pp
   Consider using
   .Sx \&Pp
   in the event of natural paragraph breaks.
 .Ss \&sp  .Ss \&sp
 .  Emits vertical space.
 .  This macro should not be used; it is implemented for compatibility with
   historical manuals.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&sp Op Cm height
   .Pp
   The
   .Cm height
   argument must be formatted as described in
   .Sx Scaling Widths .
   If unspecified,
   .Sx \&sp
   asserts a single vertical space.
 .Sh COMPATIBILITY  .Sh COMPATIBILITY
 This section documents compatibility with other roff implementations, at  This section documents compatibility between mandoc and other other
 this time limited to  troff implementations, at this time limited to GNU troff
 .Xr groff 1 .  .Pq Qq groff .
 The term  The term
 .Qq historic groff  .Qq historic groff
 refers to those versions before the  refers to groff versions before the
 .Pa doc.tmac  .Pa doc.tmac
 file re-write  file re-write
 .Pq somewhere between 1.15 and 1.19 .  .Pq somewhere between 1.15 and 1.19 .
 .  
 .Pp  .Pp
   Heirloom troff, the other significant troff implementation accepting
   \-mdoc, is similar to historic groff.
   .Pp
 .Bl -dash -compact  .Bl -dash -compact
 .It  .It
   The \es (font size), \em (font colour), and \eM (font filling colour)
   font decoration escapes are all discarded in mandoc.
   .It
   Old groff fails to assert a newline before
   .Sx \&Bd Fl ragged compact .
   .It
   groff behaves inconsistently when encountering
   .Pf non- Sx \&Fa
   children of
   .Sx \&Fo
   regarding spacing between arguments.
   In mandoc, this is not the case: each argument is consistently followed
   by a single space and the trailing
   .Sq \&)
   suppresses prior spacing.
   .It
   groff behaves inconsistently when encountering
   .Sx \&Ft
   and
   .Sx \&Fn
   in the
   .Em SYNOPSIS :
   at times newline(s) are suppressed depending on whether a prior
   .Sx \&Fn
   has been invoked.
   In mandoc, this is not the case.
   See
   .Sx \&Ft
   and
   .Sx \&Fn
   for the normalised behaviour.
   .It
   Historic groff does not break before an
   .Sx \&Fn
   when not invoked as the line macro in the
   .Em SYNOPSIS
   section.
   .It
   Historic groff formats the
   .Sx \&In
   badly: trailing arguments are trashed and
   .Em SYNOPSIS
   is not specially treated.
   .It
   groff does not accept the
   .Sq \&Ta
   pseudo-macro as a line macro.
   mandoc does.
   .It
 The comment syntax  The comment syntax
 .Sq \e."  .Sq \e\."
 is no longer accepted.  is no longer accepted.
 .It  .It
 In  In groff, the
 .Xr groff 1 ,  
 the  
 .Sx \&Pa  .Sx \&Pa
 macro does not format its arguments when used in the FILES section under  macro does not format its arguments when used in the FILES section under
 certain list types.  This irregular behaviour has been discontinued.  certain list types.
   mandoc does.
 .It  .It
 Historic  Historic groff does not print a dash for empty
 .Xr groff 1  
 does not print a dash for empty  
 .Sx \&Fl  .Sx \&Fl
 arguments.  This behaviour has been discontinued.  arguments.
   mandoc and newer groff implementations do.
 .It  .It
 .Xr groff 1  groff behaves irregularly when specifying
 behaves strangely (even between versions) when specifying  
 .Sq \ef  .Sq \ef
 escapes within line-macro scopes.  These aberrations have been  .Sx Text Decoration
 normalised.  within line-macro scopes.
   mandoc follows a consistent system.
 .It  .It
 Negative scaling units are now truncated to zero instead of creating  In mandoc, negative scaling units are truncated to zero; groff would
 interesting conditions, such as with  move to prior lines.
 .Sx \&sp  
 .Fl 1i .  
 Furthermore, the  Furthermore, the
 .Sq f  .Sq f
 scaling unit, while accepted, is rendered as the default unit.  scaling unit, while accepted, is rendered as the default unit.
 .It  .It
 In quoted literals, groff allowed pair-wise double-quotes to produce a  In quoted literals, groff allowed pair-wise double-quotes to produce a
 standalone double-quote in formatted output.  This idiosyncratic  standalone double-quote in formatted output.
 behaviour is no longer applicable.  This idiosyncratic behaviour is not applicable in mandoc.
 .It  .It
 Display types  Display offsets
 .Sx \&Bd  .Sx \&Bd
 .Fl center  .Fl offset Ar center
 and  and
 .Fl right  .Fl offset Ar right
 are aliases for  are disregarded in mandoc.
 .Fl left .  Furthermore, troff specifies a
 The  
 .Fl file Ar file  .Fl file Ar file
 argument is ignored.  Since text is not right-justified,  argument that is not supported in mandoc.
   Lastly, since text is not right-justified in mandoc (or even groff),
 .Fl ragged  .Fl ragged
 and  and
 .Fl filled  .Fl filled
Line 1972  are aliases, as are
Line 2808  are aliases, as are
 and  and
 .Fl unfilled .  .Fl unfilled .
 .It  .It
 Blocks of whitespace are stripped from both macro and free-form text  Historic groff has many un-callable macros.
 lines (except when in literal mode), while groff would retain whitespace  Most of these (excluding some block-level macros) are now callable.
 in free-form text lines.  
 .It  .It
 Historic groff has many un-callable macros.  Most of these (excluding  
 some block-level macros) are now callable, conforming to the  
 non-historic groff version.  
 .It  
 The vertical bar  The vertical bar
 .Sq \(ba  .Sq \(ba
 made historic groff  made historic groff
 .Qq go orbital  .Qq go orbital
 but is a proper delimiter in this implementation.  but has been a proper delimiter since then.
 .It  .It
 .Sx \&It  .Sx \&It Fl nested
 .Fl nested  
 is assumed for all lists (it wasn't in historic groff): any list may be  is assumed for all lists (it wasn't in historic groff): any list may be
 nested and  nested and
 .Fl enum  .Fl enum
Line 1996  lists will restart the sequence only for the sub-list.
Line 2826  lists will restart the sequence only for the sub-list.
 Some manuals use  Some manuals use
 .Sx \&Li  .Sx \&Li
 incorrectly by following it with a reserved character and expecting the  incorrectly by following it with a reserved character and expecting the
 delimiter to render.  This is not supported.  delimiter to render.
   This is not supported in mandoc.
 .It  .It
 In groff, the  In groff, the
 .Sx \&Fo  .Sx \&Cd ,
 macro only produces the first parameter.  This is no longer the case.  .Sx \&Er ,
   .Sx \&Ex ,
   and
   .Sx \&Rv
   macros were stipulated only to occur in certain manual sections.
   mandoc does not have these restrictions.
   .It
   Newer groff and mandoc print
   .Qq AT&T UNIX
   prior to unknown arguments of
   .Sx \&At ;
   older groff did nothing.
 .El  .El
 .  
 .  
 .Sh SEE ALSO  .Sh SEE ALSO
 .Xr mandoc 1 ,  .Xr mandoc 1 ,
 .Xr mandoc_char 7  .Xr mandoc_char 7
 .  
 .  
 .Sh AUTHORS  .Sh AUTHORS
 The  The
 .Nm  .Nm
 reference was written by  reference was written by
 .An Kristaps Dzonsons Aq kristaps@kth.se .  .An Kristaps Dzonsons Aq kristaps@bsd.lv .
 .\"  
 .\" XXX: this really isn't the place for these caveats.  
 .\" .  
 .\" .  
 .\" .Sh CAVEATS  
 .\" There are many ambiguous parts of mdoc.  
 .\" .  
 .\" .Pp  
 .\" .Bl -dash -compact  
 .\" .It  
 .\" .Sq \&Fa  
 .\" should be  
 .\" .Sq \&Va  
 .\" as function arguments are variables.  
 .\" .It  
 .\" .Sq \&Ft  
 .\" should be  
 .\" .Sq \&Vt  
 .\" as function return types are still types.  Furthermore, the  
 .\" .Sq \&Ft  
 .\" should be removed and  
 .\" .Sq \&Fo ,  
 .\" which ostensibly follows it, should follow the same convention as  
 .\" .Sq \&Va .  
 .\" .It  
 .\" .Sq \&Va  
 .\" should formalise that only one or two arguments are acceptable: a  
 .\" variable name and optional, preceding type.  
 .\" .It  
 .\" .Sq \&Fd  
 .\" is ambiguous.  It's commonly used to indicate an include file in the  
 .\" synopsis section.  
 .\" .Sq \&In  
 .\" should be used, instead.  
 .\" .It  
 .\" Only the  
 .\" .Sq \-literal  
 .\" argument to  
 .\" .Sq \&Bd  
 .\" makes sense.  The remaining ones should be removed.  
 .\" .It  
 .\" The  
 .\" .Sq \&Xo  
 .\" and  
 .\" .Sq \&Xc  
 .\" macros should be deprecated.  
 .\" .It  
 .\" The  
 .\" .Sq \&Dt  
 .\" macro lacks clarity.  It should be absolutely clear which title will  
 .\" render when formatting the manual page.  
 .\" .It  
 .\" A  
 .\" .Sq \&Lx  
 .\" should be provided for Linux (\(`a la  
 .\" .Sq \&Ox ,  
 .\" .Sq \&Nx  
 .\" etc.).  
 .\" .It  
 .\" There's no way to refer to references in  
 .\" .Sq \&Rs/Re  
 .\" blocks.  
 .\" .It  
 .\" The \-split and \-nosplit dictates via  
 .\" .Sq \&An  
 .\" are re-set when entering and leaving the AUTHORS section.  
 .\" .El  
 .\" .  
Legend:
Removed from v.1.92  
changed lines
  Added in v.1.140
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