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version 1.1, 2009/03/13 07:46:10 version 1.139, 2010/07/19 15:43:10
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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  .\" purpose with or without fee is hereby granted, provided that the above
 .\" above copyright notice and this permission notice appear in all  .\" copyright notice and this permission notice appear in all copies.
 .\" copies.  
 .\"  .\"
 .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL  .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 .\" WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED  .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 .\" WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE  .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 .\" AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL  .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 .\" DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR  .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 .\" PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER  .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR  .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\" PERFORMANCE OF THIS SOFTWARE.  .\"
 .\"  
 .Dd $Mdocdate$  .Dd $Mdocdate$
 .Dt mdoc 7  .Dt MDOC 7
 .Os  .Os
 .\" SECTION  
 .Sh NAME  .Sh NAME
 .Nm mdoc  .Nm mdoc
 .Nd mdoc macro reference  .Nd mdoc language reference
 .\" SECTION  
 .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.  An  manuals.
   In this reference document, we describe its syntax, structure, and
   usage.
   Our reference implementation is mandoc; the
   .Sx COMPATIBILITY
   section describes compatibility with other troff \-mdoc implementations.
   .Pp
   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.
 prior macros.  Macros are either two or three characters in length.  Other lines are interpreted within the scope of
 .\" SECTION  prior macros:
 .Sh CHARACTER ENCODING  .Bd -literal -offset indent
   \&.Sh Macro lines change control state.
   Other lines are interpreted within the current state.
   .Ed
   .Sh LANGUAGE SYNTAX
 .Nm  .Nm
 documents may contain only printable alphanumeric characters, the space  documents may contain only graphable 7-bit ASCII characters, the space
 character  character, and, in certain circumstances, the tab character.
 .Sq \  ,  
 and, in certain circumstances, the tab character  
 .Sq \et .  
 All manuals must have  All manuals must have
 .Sq \en  .Ux
 line termination.  line terminators.
 .\" SUB-SECTION  .Ss Comments
 .Ss Special Characters  Text following a
 Within a macro line, the following characters are special:  .Sq \e\*q ,
 .\" PARAGRAPH  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,
   .Sq \&.\e\*q ,
   is also ignored.
   Macro lines with only a control character and optionally whitespace are
   stripped from input.
   .Ss Reserved Characters
   Within a macro line, the following characters are reserved:
 .Pp  .Pp
 .Bl -tag -width Ds -offset XXXX -compact  .Bl -tag -width Ds -offset indent -compact
 .It \&.  .It \&.
 period  .Pq period
 .It \&,  .It \&,
 comma  .Pq comma
 .It \&:  .It \&:
 colon  .Pq colon
 .It \&;  .It \&;
 semicolon  .Pq semicolon
 .It \&(  .It \&(
 left-parenthesis  .Pq left-parenthesis
 .It \&)  .It \&)
 right-parenthesis  .Pq right-parenthesis
 .It \&[  .It \&[
 left-bracket  .Pq left-bracket
 .It \&]  .It \&]
 right-bracket  .Pq right-bracket
 .It \&?  .It \&?
 question  .Pq question
 .It \&!  .It \&!
 exclmamation  .Pq exclamation
   .It \&|
   .Pq vertical bar
 .El  .El
 .Pp  .Pp
 Use of these characters must either be escaped with a non-breaking space  Use of reserved characters is described in
   .Sx MACRO SYNTAX .
   For general use in macro lines, these characters must either be escaped
   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.
 .\" SUB-SECTION  
 .Ss Special Characters  .Ss Special Characters
 Special character sequences begin with the escape character  Special characters may occur in both macro and free-form lines.
 .Sq \\  Sequences begin with the escape character
 and followed by either an open-parenthesis  .Sq \e
   followed by either an open-parenthesis
 .Sq \&(  .Sq \&(
 for two-character sequences; an open-bracket  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.  or a single one-character sequence.
   See
   .Xr mandoc_char 7
   for a complete list.
   Examples include
   .Sq \e(em
   .Pq em-dash
   and
   .Sq \ee
   .Pq back-slash .
   .Ss Text Decoration
   Terms may be text-decorated using the
   .Sq \ef
   escape followed by an indicator: B (bold), I, (italic), R (Roman), or P
   (revert to previous mode):
 .Pp  .Pp
 Characters may alternatively be escaped by a slash-asterisk,  .D1 \efBbold\efR \efIitalic\efP
 .Sq \\* ,  
 with the same combinations as described above.  This form, however, is  
 deprecated.  The following is a table of all available escapes, arranged  
 by classification.  
 .Pp  .Pp
 Grammatic:  A numerical representation 3, 2, or 1 (bold, italic, and Roman,
   respectively) may be used instead.
   A text decoration is valid within
   the current font scope only: if a macro opens a font scope alongside
   its own scope, such as
   .Sx \&Bf
   .Cm \&Sy ,
   in-scope invocations of
   .Sq \ef
   are only valid within the font scope of the macro.
   If
   .Sq \ef
   is specified outside of any font scope, such as in unenclosed, free-form
   text, it will affect the remainder of the document.
 .Pp  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  Note this form is
 .It \\(em  .Em not
 .Pq em-dash  recommended for
 .It \\(en  .Nm ,
 .Pq en-dash  which encourages semantic annotation.
 .It \e-  .Ss Predefined Strings
 .Pq hyphen  Historically,
 .It \\\\  .Xr groff 1
 .Pq back-slash  also defined a set of package-specific
 .It \e'  .Dq predefined strings ,
 .Pq apostrophe  which, like
 .It \e`  .Sx Special Characters ,
 .Pq back-tick  mark special output characters and strings by way of input codes.
 .It \\  Predefined strings are escaped with the slash-asterisk,
 .Pq space  .Sq \e* :
 .It \\.  single-character
 .Pq period  .Sq \e*X ,
 .El  two-character
 .\" PARAGRAPH  .Sq \e*(XX ,
   and N-character
   .Sq \e*[N] .
   See
   .Xr mandoc_char 7
   for a complete list.
   Examples include
   .Sq \e*(Am
   .Pq ampersand
   and
   .Sq \e*(Ba
   .Pq vertical bar .
   .Ss Whitespace
   Whitespace consists of the space character.
   In free-form lines, whitespace is preserved within a line; un-escaped
   trailing spaces are stripped from input (unless in a literal context).
   Blank free-form lines, which may include whitespace, are only permitted
   within literal contexts.
 .Pp  .Pp
 Enclosures:  In macro lines, whitespace delimits arguments and is discarded.
   If arguments are quoted, whitespace within the quotes is retained.
   .Ss Quotation
   Macro arguments may be quoted with a double-quote to group
   space-delimited terms or to retain blocks of whitespace.
   A quoted argument begins with a double-quote preceded by whitespace.
   The next double-quote not pair-wise adjacent to another double-quote
   terminates the literal, regardless of surrounding whitespace.
 .Pp  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  This produces tokens
 .It \\(rC  .Sq a" ,
 .Pq right brace  .Sq b c ,
 .It \\(lC  .Sq de ,
 .Pq left brace  and
 .It \\(ra  .Sq fg" .
 .Pq right angle  Note that any quoted term, be it argument or macro, is indiscriminately
 .It \\(la  considered literal text.
 .Pq left angle  Thus, the following produces
 .It \\(rB  .Sq \&Em a :
 .Pq right bracket  .Bd -literal -offset indent
 .It \\(lB  \&.Em "Em a"
 .Pq left bracket  .Ed
 .It \\q  
 .Pq double-quote  
 .It \\(lq  
 .Pq left double-quote  
 .It \\(Lq  
 .Pq left double-quote, deprecated  
 .It \\(rq  
 .Pq right double-quote  
 .It \\(Rq  
 .Pq right double-quote, deprecated  
 .It \\(oq  
 .Pq left single-quote  
 .It \\(aq  
 .Pq right single-quote  
 .El  
 .\" PARAGRAPH  
 .Pp  .Pp
 Indicatives:  In free-form mode, quotes are regarded as opaque text.
   .Ss Dates
   There are several macros in
   .Nm
   that require a date argument.
   The canonical form for dates is the American format:
 .Pp  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  .D1 Cm Month Day , Year
 .It \\(<-  
 .Pq left arrow  
 .It \\(->  
 .Pq right arrow  
 .It \\(ua  
 .Pq up arrow  
 .It \\(da  
 .Pq down arrow  
 .El  
 .\" PARAGRAPH  
 .Pp  .Pp
 Mathematical:  The
   .Cm Day
   value is an optionally zero-padded numeral.
   The
   .Cm Month
   value is the full month name.
   The
   .Cm Year
   value is the full four-digit year.
 .Pp  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  Reduced form dates are broken-down canonical form dates:
 .It \\(Gt  .Pp
 .Pq greater-than, deprecated  .D1 Cm Month , Year
 .It \\(Lt  .D1 Cm Year
 .Pq less-than, deprecated  .Pp
 .It \\(<=  Some examples of valid dates follow:
 .Pq less-than-equal  .Pp
 .It \\(Le  .D1 "May, 2009" Pq reduced form
 .Pq less-than-equal, deprecated  .D1 "2009" Pq reduced form
 .It \\(>=  .D1 "May 20, 2009" Pq canonical form
 .Pq greater-than-equal  .Ss Scaling Widths
 .It \\(Ge  Many macros support scaled widths for their arguments, such as
 .Pq greater-than-equal  stipulating a two-inch list indentation with the following:
 .It \\(==  .Bd -literal -offset indent
 .Pq equal  \&.Bl -tag -width 2i
 .It \\(!=  .Ed
 .Pq not equal  .Pp
 .It \\(Ne  The syntax for scaled widths is
 .Pq not equal, deprecated  .Sq Li [+-]?[0-9]*.[0-9]*[:unit:] ,
 .It \\(if  where a decimal must be preceded or proceeded by at least one digit.
 .Pq infinity  Negative numbers, while accepted, are truncated to zero.
 .It \\(If  The following scaling units are accepted:
 .Pq infinity, deprecated  .Pp
 .It \\(na  .Bl -tag -width Ds -offset indent -compact
 .Pq NaN , an extension  .It c
 .It \\(Na  centimetre
 .Pq NaN, deprecated  .It i
 .It \\(+-  inch
 .Pq plus-minus  .It P
 .It \\(Pm  pica (~1/6 inch)
 .Pq plus-minus, deprecated  .It p
 .It \\(**  point (~1/72 inch)
 .Pq asterisk  .It f
   synonym for
   .Sq u
   .It v
   default vertical span
   .It m
   width of rendered
   .Sq m
   .Pq em
   character
   .It n
   width of rendered
   .Sq n
   .Pq en
   character
   .It u
   default horizontal span
   .It M
   mini-em (~1/100 em)
 .El  .El
 .\" PARAGRAPH  
 .Pp  .Pp
 Diacritics:  Using anything other than
   .Sq m ,
   .Sq n ,
   .Sq u ,
   or
   .Sq v
   is necessarily non-portable across output media.
   See
   .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  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  The proper spacing is also intelligently preserved if a sentence ends at
 .It \\(ga  the boundary of a macro line, e.g.,
 .Pq accent grave  .Pp
 .It \\(aa  .D1 \&Xr mandoc 1 \.
 .Pq accent accute  .D1 \&Fl T \&Ns \&Cm ascii \.
   .Sh MANUAL STRUCTURE
   A well-formed
   .Nm
   document consists of a document prologue followed by one or more
   sections.
   .Pp
   The prologue, which consists of (in order) the
   .Sx \&Dd ,
   .Sx \&Dt ,
   and
   .Sx \&Os
   macros, is required for every document.
   .Pp
   The first section (sections are denoted by
   .Sx \&Sh )
   must be the NAME section, consisting of at least one
   .Sx \&Nm
   followed by
   .Sx \&Nd .
   .Pp
   Following that, convention dictates specifying at least the
   .Em SYNOPSIS
   and
   .Em DESCRIPTION
   sections, although this varies between manual sections.
   .Pp
   The following is a well-formed skeleton
   .Nm
   file:
   .Bd -literal -offset indent
   \&.Dd $\&Mdocdate$
   \&.Dt mdoc 7
   \&.Os
   \&.Sh NAME
   \&.Nm foo
   \&.Nd a description goes here
   \&.\e\*q The next is for sections 2, 3, & 9 only.
   \&.\e\*q .Sh LIBRARY
   \&.Sh SYNOPSIS
   \&.Nm foo
   \&.Op Fl options
   \&.Ar
   \&.Sh DESCRIPTION
   The
   \&.Nm
   utility processes files ...
   \&.\e\*q .Sh IMPLEMENTATION NOTES
   \&.\e\*q The next is for sections 2, 3, & 9 only.
   \&.\e\*q .Sh RETURN VALUES
   \&.\e\*q The next is for sections 1, 6, 7, & 8 only.
   \&.\e\*q .Sh ENVIRONMENT
   \&.\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 The next is for sections 1, 4, 6, 7, & 8 only.
   \&.\e\*q .Sh DIAGNOSTICS
   \&.\e\*q The next is for sections 2, 3, & 9 only.
   \&.\e\*q .Sh ERRORS
   \&.\e\*q .Sh SEE ALSO
   \&.\e\*q .Xr foobar 1
   \&.\e\*q .Sh STANDARDS
   \&.\e\*q .Sh HISTORY
   \&.\e\*q .Sh AUTHORS
   \&.\e\*q .Sh CAVEATS
   \&.\e\*q .Sh BUGS
   \&.\e\*q .Sh SECURITY CONSIDERATIONS
   .Ed
   .Pp
   The sections in a
   .Nm
   document are conventionally ordered as they appear above.
   Sections should be composed as follows:
   .Bl -ohang -offset Ds
   .It Em NAME
   The name(s) and a short description of the documented material.
   The syntax for this as follows:
   .Bd -literal -offset indent
   \&.Nm name0
   \&.Nm name1
   \&.Nm name2
   \&.Nd a short description
   .Ed
   .Pp
   The
   .Sx \&Nm
   macro(s) must precede the
   .Sx \&Nd
   macro.
   .Pp
   See
   .Sx \&Nm
   and
   .Sx \&Nd .
   .It Em LIBRARY
   The name of the library containing the documented material, which is
   assumed to be a function in a section 2, 3, or 9 manual.
   The syntax for this is as follows:
   .Bd -literal -offset indent
   \&.Lb libarm
   .Ed
   .Pp
   See
   .Sx \&Lb .
   .It Em SYNOPSIS
   Documents the utility invocation syntax, function call syntax, or device
   configuration.
   .Pp
   For the first, utilities (sections 1, 6, and 8), this is
   generally structured as follows:
   .Bd -literal -offset indent
   \&.Nm foo
   \&.Op Fl v
   \&.Op Fl o Ar file
   \&.Op Ar
   \&.Nm bar
   \&.Op Fl v
   \&.Op Fl o Ar file
   \&.Op Ar
   .Ed
   .Pp
   For the second, function calls (sections 2, 3, 9):
   .Bd -literal -offset indent
   \&.Vt extern const char *global;
   \&.In header.h
   \&.Ft "char *"
   \&.Fn foo "const char *src"
   \&.Ft "char *"
   \&.Fn bar "const char *src"
   .Ed
   .Pp
   And for the third, configurations (section 4):
   .Bd -literal -offset indent
   \&.Cd \*qit* at isa? port 0x2e\*q
   \&.Cd \*qit* at isa? port 0x4e\*q
   .Ed
   .Pp
   Manuals not in these sections generally don't need a
   .Em SYNOPSIS .
   .Pp
   Some macros are displayed differently in the
   .Em SYNOPSIS
   section, particularly
   .Sx \&Nm ,
   .Sx \&Cd ,
   .Sx \&Fd ,
   .Sx \&Fn ,
   .Sx \&Fo ,
   .Sx \&In ,
   .Sx \&Vt ,
   and
   .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
   This expands upon the brief, one-line description in
   .Em NAME .
   It usually contains a break-down of the options (if documenting a
   command), such as:
   .Bd -literal -offset indent
   The arguments are as follows:
   \&.Bl \-tag \-width Ds
   \&.It Fl v
   Print verbose information.
   \&.El
   .Ed
   .Pp
   Manuals not documenting a command won't include the above fragment.
   .It Em IMPLEMENTATION NOTES
   Implementation-specific notes should be kept here.
   This is useful when implementing standard functions that may have side
   effects or notable algorithmic implications.
   .It Em RETURN VALUES
   This section is the dual of
   .Em EXIT STATUS ,
   which is used for commands.
   It documents the return values of functions in sections 2, 3, and 9.
   .Pp
   See
   .Sx \&Rv .
   .It Em ENVIRONMENT
   Documents any usages of environment variables, e.g.,
   .Xr environ 7 .
   .Pp
   See
   .Sx \&Ev .
   .It Em FILES
   Documents files used.
   It's helpful to document both the file and a short description of how
   the file is used (created, modified, etc.).
   .Pp
   See
   .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
   Example usages.
   This often contains snippets of well-formed, well-tested invocations.
   Make doubly sure that your examples work properly!
   .It Em DIAGNOSTICS
   Documents error conditions.
   This is most useful in section 4 manuals.
   Historically, this section was used in place of
   .Em EXIT STATUS
   for manuals in sections 1, 6, and 8; however, this practise is
   discouraged.
   .Pp
   See
   .Sx \&Bl
   .Fl diag .
   .It Em ERRORS
   Documents error handling in sections 2, 3, and 9.
   .Pp
   See
   .Sx \&Er .
   .It Em SEE ALSO
   References other manuals with related topics.
   This section should exist for most manuals.
   Cross-references should conventionally be ordered first by section, then
   alphabetically.
   .Pp
   See
   .Sx \&Xr .
   .It Em STANDARDS
   References any standards implemented or used.
   If not adhering to any standards, the
   .Em HISTORY
   section should be used instead.
   .Pp
   See
   .Sx \&St .
   .It Em HISTORY
   The history of any manual without a
   .Em STANDARDS
   section should be described in this section.
   .It Em AUTHORS
   Credits to authors, if applicable, should appear in this section.
   Authors should generally be noted by both name and an e-mail address.
   .Pp
   See
   .Sx \&An .
   .It Em CAVEATS
   Explanations of common misuses and misunderstandings should be explained
   in this section.
   .It Em BUGS
   Extant bugs should be described in this section.
   .It Em SECURITY CONSIDERATIONS
   Documents any security precautions that operators should consider.
 .El  .El
 .\" PARAGRAPH  .Sh MACRO SYNTAX
   Macros are one to three three characters in length and begin with a
   control character ,
   .Sq \&. ,
   at the beginning of the line.
   An arbitrary amount of whitespace may sit between the control character
   and the macro name.
   Thus, the following are equivalent:
   .Bd -literal -offset indent
   \&.Pp
   \&.\ \ \ \&Pp
   .Ed
 .Pp  .Pp
 Special symbols:  The syntax of a macro depends on its classification.
   In this section,
   .Sq \-arg
   refers to macro arguments, which may be followed by zero or more
   .Sq parm
   parameters;
   .Sq \&Yo
   opens the scope of a macro; and if specified,
   .Sq \&Yc
   closes it out.
 .Pp  .Pp
 .Bl -tag -width 12n -offset "XXXX" -compact  The
 .It \\(bu  .Em Callable
 .Pq bullet  column indicates that the macro may be called subsequent to the initial
 .It \\(ba  line-macro.
 .Pq bar  If a macro is not callable, then its invocation after the initial line
 .It \\(Ba  macro is interpreted as opaque text, such that
 .Pq bar, deprecated  .Sq \&.Fl \&Sh
 .It \\(co  produces
 .Pq copyright  .Sq Fl \&Sh .
 .It \\&  .Pp
 .Pq non-breaking space  The
 .It \\e  .Em Parsable
 .Pq escape  column indicates whether the macro may be followed by further
 .It \\(Am  (ostensibly callable) macros.
 .Pq ampersand, deprecated  If a macro is not parsable, subsequent macro invocations on the line
 .El  will be interpreted as opaque text.
 .\" SECTION  .Pp
 .Sh CLASSIFICATION  The
 Macros are classified in an ontology described by scope rules.  .Em Scope
 .Bl -tag -width "in-lineX"  column, if applicable, describes closure rules.
 .\" LIST-ITEM  .Ss Block full-explicit
 .It Em Block  Multi-line scope closed by an explicit closing macro.
 Block macros enclose other block macros, in-line macros or text, and  All macros contains bodies; only
 may span multiple lines.  .Sx \&Bf
 .Qq Implicit  contains a head.
 block scope is closed by a subsequent invocation of the same macro,  .Bd -literal -offset indent
 one of a set of corresponding closure macros or end-of-file.  \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
 .Qq Explicit  \(lBbody...\(rB
 block scope is closed by a corresponding closure macro.  \&.Yc
 .Bl -tag -width "partial-blockX"  .Ed
 .\" LIST-ITEM  .Pp
 .It Em Full-block  .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"
 Always spans multiple lines.  Consists optionally of one or more  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
 .Qq heads ,  .It Sx \&Bd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ed
 subsequent macros or text on the same line following invocation; a  .It Sx \&Bf  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ef
 .Qq body ,  .It Sx \&Bk  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ek
 which spans subsequent lines of text or macros; and an optional  .It Sx \&Bl  Ta    \&No     Ta    \&No     Ta    closed by Sx \&El
 .Qq tail ,  .It Sx \&Ed  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bd
 macros or text on the same line following closure.  .It Sx \&Ef  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bf
 .\" LIST-ITEM  .It Sx \&Ek  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bk
 .It Em Partial-block  .It Sx \&El  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Bl
 May span multiple lines.  Consists optionally of a  
 .Qq head ,  
 text immediately following invocation; always a  
 .Qq body ,  
 text or macros following the head on the same and subsequent lines; and  
 optionally a  
 .Qq tail ,  
 text immediately following closure.  
 .El  .El
 .\" LIST-ITEM  
 .It Em In-line  
 In-line macros may only enclose text and span at most a single line.  If  
 a macro is parsable, its scope may be closed by subsequent macros or  
 delimiting punctuation.  In-line macros follow different conventions for  
 closure; see  
 .Sx MACROS  
 for per-macro details.  
 .El  
 .\" .\" SUB-SECTION  
 .\" .Ss Examples  
 .\" The following examples illustrate each macro classification.  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Implicit full-block.  Has head, body and no tail.  Scope closed by  
 .\" second  
 .\" .Sq \&Sh  
 .\" invocation.  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Sh SECTION 1  
 .\" body...  
 .\" \&.Sh SECTION 2  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Nested implicit full-block, where the subsection  
 .\" .Sq \&Ss  
 .\" is within the scope of the parent section  
 .\" .Sq \&Sh  
 .\" and closed along with its parent by the subsequent  
 .\" .Sq \&Sh .  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Sh SECTION 1  
 .\" \&.Ss Subsection 1  
 .\" body...  
 .\" \&.Sh SECTION 2  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Explicit full-block.  Has a head, a body and no tail.  Scope closed by  
 .\" .Sq \&Ef  
 .\" invocation.  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Bf symbolic  
 .\" body...  
 .\" \&.Ef  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Nested explicit/implicit scope.  
 .\" .Sq \&It  
 .\" macro is an implicit block whose scope is closed by the explicit  
 .\" .Sq \&El  
 .\" closure.  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Bl \-bullet  
 .\" \&.It head  
 .\" body...  
 .\" \&.El  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Explicit partial-block.  Has head, body and tail.  Scope closed by  
 .\" .Sq \&Ec  
 .\" invocation.  
 .\" .Bd -literal -offset XXX  
 .\" \&.Eo head body... \&Ec tail  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Implicit partial-block.  Has only body.  Scope is closed by end-of-line.  
 .\" .Bd -literal -offset XXX  
 .\" \&.Sq body...  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Explicit partial-block with only body and scope closed by  
 .\" .Sq \&Ac  
 .\" invocation.  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Ao body... \&Ac  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Implicit partial-block enclosing explicit partial-block.  
 .\" .Bd -literal -offset XXX  
 .\" \&.Sq body... \&Ao body... \&Ac  
 .\" .Ed  
 .\" .\" PARAGRAPH  
 .\" .Pp  
 .\" Inline macros, several in sequence.  Scope is closed for  
 .\" .Sq \&Fl  
 .\" by the punctuation delimiter and  
 .\" .Sq \&Ar  
 .\" by the end-of-line.  
 .\" .Bd -literal -offset XXXX  
 .\" \&.Fl text0 text1 ; Ar text0 text1  
 .\" .Ed  
 .\" SECTION  
 .Sh MACROS  
 This section contains a complete list of all  
 .Nm  
 macros, arranged ontologically then alphanumerically by macro name.  A  
 .Qq callable  
 macro is may be invoked subsequent to the initial macro-line macro.  A  
 .Qq parsable  
 macro May be followed by further (ostensibly callable) macros.  
 .\" SUB-SECTION  
 .Ss Block full-implicit  .Ss Block full-implicit
 The head of these macros follows invocation; the body is the content of  Multi-line scope closed by end-of-file or implicitly by another macro.
 subsequent lines prior to closure.  None of these macros have tails;  All macros have bodies; some
 some  
 .Po  .Po
 .Sq \&It \-bullet ,  .Sx \&It Fl bullet ,
 .Sq \-hyphen ,  .Fl hyphen ,
 .Sq \-dash ,  .Fl dash ,
 .Sq \-enum  .Fl enum ,
   .Fl item
 .Pc  .Pc
 don't have heads.  don't have heads; only one
   .Po
   .Sx \&It Fl column
   .Pc
   has multiple heads.
   .Bd -literal -offset indent
   \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead... \(lBTa head...\(rB\(rB
   \(lBbody...\(rB
   .Ed
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" "Closing" -compact -offset XXXX  .Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Closing  .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
 .It \&.Sh    Ta    \&No    Ta    \&No    Ta    \&.Sh  .It Sx \&It  Ta    \&No     Ta    Yes      Ta    closed by Sx \&It , Sx \&El
 .It \&.Ss    Ta    \&No    Ta    \&No    Ta    \&.Sh, \&.Ss  .It Sx \&Nd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh
 .It \&.It    Ta    \&No    Ta    Yes     Ta    \&.It, \&.El  .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 \&Ss  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh , Sx \&Ss
 .El  .El
 .\" SUB-SECTION  
 .Ss Block full-explicit  
 None of these macros are callable or parsed.  The last column indicates  
 the explicit scope rules.  All contains bodies, some may contain heads  
 .Pq So \&Bf Sc .  
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXX" -compact -offset XXXX  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
   Like block full-explicit, but also with single-line scope.
   Each has at least a body and, in limited circumstances, a head
   .Po
   .Sx \&Fo ,
   .Sx \&Eo
   .Pc
   and/or tail
   .Pq Sx \&Ec .
   .Bd -literal -offset indent
   \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
   \(lBbody...\(rB
   \&.Yc \(lBtail...\(rB
   
   \&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB \
   \(lBbody...\(rB \&Yc \(lBtail...\(rB
   .Ed
   .Pp
   .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
 .It \&.Bd    Ta    \&No    Ta    \&No    Ta    closed by \&.Ed  .It Sx \&Ac  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Ao
 .It \&.Ed    Ta    \&No    Ta    \&No    Ta    opened by \&.Bd  .It Sx \&Ao  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Ac
 .It \&.Bl    Ta    \&No    Ta    \&No    Ta    closed by \&.El  .It Sx \&Bc  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Bo
 .It \&.El    Ta    \&No    Ta    \&No    Ta    opened by \&.Bl  .It Sx \&Bo  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Bc
 .It \&.Bf    Ta    \&No    Ta    \&No    Ta    closed by \&.Ef  .It Sx \&Brc Ta    Yes      Ta    Yes      Ta    opened by Sx \&Bro
 .It \&.Ef    Ta    \&No    Ta    \&No    Ta    opened by \&.Bf  .It Sx \&Bro Ta    Yes      Ta    Yes      Ta    closed by Sx \&Brc
   .It Sx \&Dc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Do
   .It Sx \&Do  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Dc
   .It Sx \&Ec  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Eo
   .It Sx \&Eo  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Ec
   .It Sx \&Fc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Fo
   .It Sx \&Fo  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Fc
   .It Sx \&Oc  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Oo
   .It Sx \&Oo  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Oc
   .It Sx \&Pc  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Po
   .It Sx \&Po  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Pc
   .It Sx \&Qc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Oo
   .It Sx \&Qo  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Oc
   .It Sx \&Re  Ta    \&No     Ta    \&No     Ta    opened by Sx \&Rs
   .It Sx \&Rs  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Re
   .It Sx \&Sc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&So
   .It Sx \&So  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Sc
   .It Sx \&Xc  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Xo
   .It Sx \&Xo  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Xc
 .El  .El
 .\" SUB-SECTION  
 .Ss Block partial-implicit  .Ss Block partial-implicit
 All of these are callable and parsed for further macros.  Their scopes  Like block full-implicit, but with single-line scope closed by
 close at the invocation's end-of-line.  .Sx Reserved Characters
   or end of line.
   .Bd -literal -offset indent
   \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
   .Ed
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset XXXX  .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
 .It \&.Aq    Ta    Yes   Ta    Yes  .It Sx \&Aq  Ta    Yes      Ta    Yes
 .It \&.Op    Ta    Yes   Ta    Yes  .It Sx \&Bq  Ta    Yes      Ta    Yes
 .It \&.Bq    Ta    Yes   Ta    Yes  .It Sx \&Brq Ta    Yes      Ta    Yes
 .It \&.Dq    Ta    Yes   Ta    Yes  .It Sx \&D1  Ta    \&No     Ta    \&Yes
 .It \&.Pq    Ta    Yes   Ta    Yes  .It Sx \&Dl  Ta    \&No     Ta    Yes
 .It \&.Qq    Ta    Yes   Ta    Yes  .It Sx \&Dq  Ta    Yes      Ta    Yes
 .It \&.Sq    Ta    Yes   Ta    Yes  .It Sx \&Op  Ta    Yes      Ta    Yes
 .It \&.Brq   Ta    Yes   Ta    Yes  .It Sx \&Pq  Ta    Yes      Ta    Yes
   .It Sx \&Ql  Ta    Yes      Ta    Yes
   .It Sx \&Qq  Ta    Yes      Ta    Yes
   .It Sx \&Sq  Ta    Yes      Ta    Yes
   .It Sx \&Vt  Ta    Yes      Ta    Yes
 .El  .El
 .\" SUB-SECTION  
 .Ss Block partial-explicit  
 Each of these contains at least a body and, in limited circumstances, a  
 head  
 .Pq So \&Fo Sc , So \&Eo Sc  
 and/or tail  
 .Pq So \&Ec Sc .  
 .Pp  .Pp
 .Bl -column "MacroX" "CallableX" "ParsableX" "closed by XXXX" -compact -offset XXXX  Note that the
 .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope  .Sx \&Vt
 .It \&.Ao    Ta    Yes   Ta    Yes    Ta    closed by \&.Ac  macro is a
 .It \&.Ac    Ta    Yes   Ta    Yes    Ta    opened by \&.Ao  .Sx Block partial-implicit
 .It \&.Bc    Ta    Yes   Ta    Yes    Ta    closed by \&.Bo  only when invoked as the first macro
 .It \&.Bo    Ta    Yes   Ta    Yes    Ta    opened by \&.Bc  in a
 .It \&.Pc    Ta    Yes   Ta    Yes    Ta    closed by \&.Po  .Em SYNOPSIS
 .It \&.Po    Ta    Yes   Ta    Yes    Ta    opened by \&.Pc  section line, else it is
 .It \&.Do    Ta    Yes   Ta    Yes    Ta    closed by \&.Dc  .Sx In-line .
 .It \&.Dc    Ta    Yes   Ta    Yes    Ta    opened by \&.Do  .Ss In-line
 .It \&.Xo    Ta    Yes   Ta    Yes    Ta    closed by \&.Xc  Closed by
 .It \&.Xc    Ta    Yes   Ta    Yes    Ta    opened by \&.Xo  .Sx Reserved Characters ,
 .It \&.Bro   Ta    Yes   Ta    Yes    Ta    closed by \&.Brc  end of line, fixed argument lengths, and/or subsequent macros.
 .It \&.Brc   Ta    Yes   Ta    Yes    Ta    opened by \&.Bro  In-line macros have only text children.
 .It \&.Oc    Ta    Yes   Ta    Yes    Ta    closed by \&.Oo  If a number (or inequality) of arguments is
 .It \&.Oo    Ta    Yes   Ta    Yes    Ta    opened by \&.Oc  .Pq n ,
 .It \&.So    Ta    Yes   Ta    Yes    Ta    closed by \&.Sc  then the macro accepts an arbitrary number of arguments.
 .It \&.Sc    Ta    Yes   Ta    Yes    Ta    opened by \&.So  .Bd -literal -offset indent
 .It \&.Fc    Ta    Yes   Ta    Yes    Ta    opened by \&.Fo  \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lbres...\(rb
 .It \&.Fo    Ta    \&No  Ta    \&No   Ta    closed by \&.Fc  
 .It \&.Ec    Ta    Yes   Ta    Yes    Ta    opened by \&.Eo  \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
 .It \&.Eo    Ta    Yes   Ta    Yes    Ta    closed by \&.Ec  
 .It \&.Qc    Ta    Yes   Ta    Yes    Ta    opened by \&.Oo  \&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
 .It \&.Qo    Ta    Yes   Ta    Yes    Ta    closed by \&.Oc  .Ed
   .Pp
   .Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent
   .It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments
   .It Sx \&%A  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%B  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%C  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%D  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%I  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%J  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%N  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%O  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%P  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%Q  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%R  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%T  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%U  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&%V  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&Ad  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&An  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Ap  Ta    Yes      Ta    Yes      Ta    0
   .It Sx \&Ar  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&At  Ta    Yes      Ta    Yes      Ta    1
   .It Sx \&Bsx Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Bt  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Bx  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Cd  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Cm  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Db  Ta    \&No     Ta    \&No     Ta    1
   .It Sx \&Dd  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&Dt  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Dv  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Dx  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Em  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&En  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Er  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Es  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Ev  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Ex  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Fa  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Fd  Ta    \&No     Ta    \&No     Ta    >0
   .It Sx \&Fl  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Fn  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Fr  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Ft  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Fx  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Hf  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Ic  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&In  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Lb  Ta    \&No     Ta    \&No     Ta    1
   .It Sx \&Li  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Lk  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Lp  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Ms  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Mt  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Nm  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&No  Ta    Yes      Ta    Yes      Ta    0
   .It Sx \&Ns  Ta    Yes      Ta    Yes      Ta    0
   .It Sx \&Nx  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Os  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Ot  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Ox  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Pa  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Pf  Ta    Yes      Ta    Yes      Ta    1
   .It Sx \&Pp  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Rv  Ta    \&No     Ta    \&No     Ta    n
   .It Sx \&Sm  Ta    \&No     Ta    \&No     Ta    1
   .It Sx \&St  Ta    \&No     Ta    Yes      Ta    1
   .It Sx \&Sx  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Sy  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Tn  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Ud  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&Ux  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Va  Ta    Yes      Ta    Yes      Ta    n
   .It Sx \&Vt  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&Xr  Ta    Yes      Ta    Yes      Ta    >0
   .It Sx \&br  Ta    \&No     Ta    \&No     Ta    0
   .It Sx \&sp  Ta    \&No     Ta    \&No     Ta    1
 .El  .El
 .\" SUB-SECTION  .Sh REFERENCE
 .Ss General  This section is a canonical reference of all macros, arranged
 .Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset XXXX  alphabetically.
 .It Em Macro Ta Em Callable Ta Em Parsable  For the scoping of individual macros, see
 .It \&.Dd    Ta    \&    Ta    \&  .Sx MACRO SYNTAX .
 .It \&.Dt    Ta    \&    Ta    \&  .Ss \&%A
 .It \&.Os    Ta    \&    Ta    \&  Author name of an
 .It \&.Pp    Ta    \&    Ta    \&  .Sx \&Rs
 .It \&.D1    Ta    \&    Ta    \&  block.
 .It \&.Dl    Ta    \&    Ta    Yes  Multiple authors should each be accorded their own
 .It \&.Ad    Ta    Yes   Ta    Yes  .Sx \%%A
 .It \&.An    Ta    \&    Ta    Yes  line.
 .It \&.Ar    Ta    Yes   Ta    Yes  Author names should be ordered with full or abbreviated forename(s)
 .It \&.Cd    Ta    Yes   Ta    \&  first, then full surname.
 .It \&.Cm    Ta    Yes   Ta    Yes  .Ss \&%B
 .It \&.Dv    Ta    Yes   Ta    Yes  Book title of an
 .It \&.Er    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Ev    Ta    Yes   Ta    Yes  block.
 .It \&.Ex    Ta    \&    Ta    \&  This macro may also be used in a non-bibliographic context when
 .It \&.Fa    Ta    Yes   Ta    Yes  referring to book titles.
 .It \&.Fd    Ta    \&    Ta    \&  .Ss \&%C
 .It \&.Fl    Ta    Yes   Ta    Yes  Publication city or location of an
 .It \&.Fn    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Ft    Ta    \&    Ta    \&  block.
 .It \&.Ic    Ta    Yes   Ta    Yes  .Pp
 .It \&.In    Ta    \&    Ta    \&  .Em Remarks :
 .It \&.Li    Ta    Yes   Ta    Yes  this macro is not implemented in
 .It \&.Nd    Ta    \&    Ta    \&  .Xr groff 1 .
 .It \&.Nm    Ta    Yes   Ta    Yes  .Ss \&%D
 .It \&.Ot    Ta    \&    Ta    \&  Publication date of an
 .It \&.Pa    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Rv    Ta    \&    Ta    \&  block.
 .It \&.St    Ta    Yes   Ta    \&  This should follow the reduced or canonical form syntax described in
 .It \&.Va    Ta    Yes   Ta    Yes  .Sx Dates .
 .It \&.Vt    Ta    Yes   Ta    Yes  .Ss \&%I
 .It \&.Xr    Ta    Yes   Ta    Yes  Publisher or issuer name of an
 .It \&.%A    Ta    \&    Ta    \&  .Sx \&Rs
 .It \&.%B    Ta    \&    Ta    \&  block.
 .It \&.%C    Ta    \&    Ta    \&  .Ss \&%J
 .It \&.%D    Ta    \&    Ta    \&  Journal name of an
 .It \&.%I    Ta    \&    Ta    \&  .Sx \&Rs
 .It \&.%J    Ta    \&    Ta    \&  block.
 .It \&.%N    Ta    \&    Ta    \&  .Ss \&%N
 .It \&.%O    Ta    \&    Ta    \&  Issue number (usually for journals) of an
 .It \&.%P    Ta    \&    Ta    \&  .Sx \&Rs
 .It \&.%R    Ta    \&    Ta    \&  block.
 .It \&.%T    Ta    \&    Ta    \&  .Ss \&%O
 .It \&.%V    Ta    \&    Ta    \&  Optional information of an
 .It \&.At    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Bsx   Ta    Yes   Ta    Yes  block.
 .It \&.Bx    Ta    Yes   Ta    Yes  .Ss \&%P
 .It \&.Db    Ta    \&    Ta    \&  Book or journal page number of an
 .It \&.Em    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Fx    Ta    Yes   Ta    Yes  block.
 .It \&.Ms    Ta    \&    Ta    Yes  .Ss \&%Q
 .It \&.No    Ta    Yes   Ta    Yes  Institutional author (school, government, etc.) of an
 .It \&.Ns    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Nx    Ta    Yes   Ta    Yes  block.
 .It \&.Ox    Ta    Yes   Ta    Yes  Multiple institutional authors should each be accorded their own
 .It \&.Pf    Ta    \&    Ta    Yes  .Sx \&%Q
 .It \&.Ql    Ta    Yes   Ta    Yes  line.
 .It \&.Re    Ta    \&    Ta    \&  .Ss \&%R
 .It \&.Rs    Ta    \&    Ta    \&  Technical report name of an
 .It \&.Sm    Ta    \&    Ta    \&  .Sx \&Rs
 .It \&.Sx    Ta    Yes   Ta    Yes  block.
 .It \&.Sy    Ta    Yes   Ta    Yes  .Ss \&%T
 .It \&.Tn    Ta    Yes   Ta    Yes  Article title of an
 .It \&.Ux    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Bk    Ta    \&    Ta    \&  block.
 .It \&.Ek    Ta    \&    Ta    \&  This macro may also be used in a non-bibliographical context when
 .It \&.Bt    Ta    \&    Ta    \&  referring to article titles.
 .It \&.Hf    Ta    \&    Ta    \&  .Ss \&%U
 .It \&.Fr    Ta    \&    Ta    \&  URI of reference document.
 .It \&.Ud    Ta    \&    Ta    \&  .Ss \&%V
 .It \&.Lb    Ta    \&    Ta    \&  Volume number of an
 .It \&.Ap    Ta    Yes   Ta    Yes  .Sx \&Rs
 .It \&.Lp    Ta    \&    Ta    \&  block.
 .It \&.Lk    Ta    \&    Ta    Yes  .Ss \&Ac
 .It \&.Mt    Ta    \&    Ta    Yes  Closes an
   .Sx \&Ao
   block.
   Does not have any tail arguments.
   .Ss \&Ad
   Address construct: usually in the context of an computational address in
   memory, not a physical (post) address.
   .Pp
   Examples:
   .D1 \&.Ad [0,$]
   .D1 \&.Ad 0x00000000
   .Ss \&An
   Author name.
   This macro may alternatively accepts the following arguments, although
   these may not be specified along with a parameter:
   .Bl -tag -width 12n -offset indent
   .It Fl split
   Renders a line break before each author listing.
   .It Fl nosplit
   The opposite of
   .Fl split .
 .El  .El
   .Pp
   In the AUTHORS section, the default is not to split the first author
   listing, but all subsequent author listings, whether or not they're
   interspersed by other macros or text, are split.
   Thus, specifying
   .Fl split
   will cause the first listing also to be split.
   If not in the AUTHORS section, the default is not to split.
   .Pp
   Examples:
   .D1 \&.An -nosplit
   .D1 \&.An J. D. Ullman .
   .Pp
   .Em Remarks :
   the effects of
   .Fl split
   or
   .Fl nosplit
   are re-set when entering the AUTHORS section, so if one specifies
   .Sx \&An Fl nosplit
   in the general document body, it must be re-specified in the AUTHORS
   section.
   .Ss \&Ao
   Begins a block enclosed by angled brackets.
   Does not have any head arguments.
   .Pp
   Examples:
   .D1 \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
   .Pp
   See also
   .Sx \&Aq .
   .Ss \&Ap
   Inserts an apostrophe without any surrounding whitespace.
   This is generally used as a grammatical device when referring to the verb
   form of a function:
   .Bd -literal -offset indent
   \&.Fn execve Ap d
   .Ed
   .Ss \&Aq
   Encloses its arguments in angled brackets.
   .Pp
   Examples:
   .D1 \&.Fl -key= \&Ns \&Aq \&Ar val
   .Pp
   .Em Remarks :
   this macro is often abused for rendering URIs, which should instead use
   .Sx \&Lk
   or
   .Sx \&Mt ,
   or to note pre-processor
   .Dq Li #include
   statements, which should use
   .Sx \&In .
   .Pp
   See also
   .Sx \&Ao .
   .Ss \&Ar
   Command arguments.
   If an argument is not provided, the string
   .Dq file ...
   is used as a default.
   .Pp
   Examples:
   .D1 \&.Fl o \&Ns \&Ar file1
   .D1 \&.Ar
   .D1 \&.Ar arg1 , arg2 .
   .Ss \&At
   Formats an AT&T version.
   Accepts at most one parameter:
   .Bl -tag -width 12n -offset indent
   .It Cm v[1-7] | 32v
   A version of
   .At .
   .It Cm V[.[1-4]]?
   A system version of
   .At .
   .El
   .Pp
   Note that these parameters do not begin with a hyphen.
   .Pp
   Examples:
   .D1 \&.At
   .D1 \&.At V.1
   .Pp
   See also
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .Ss \&Bc
   Closes a
   .Sx \&Bo
   block.
   Does not have any tail arguments.
   .Ss \&Bd
   Begins a display block.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Bd
   .Fl type
   .Op Fl offset Ar width
   .Op Fl compact
   .Ed
   .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
   following arguments:
   .Bl -tag -width 12n -offset indent
   .It Fl ragged
   Only left-justify the block.
   .It Fl unfilled
   Do not justify the block at all.
   .It Fl filled
   Left- and right-justify the block.
   .It Fl literal
   Alias for
   .Fl unfilled .
   .It Fl centered
   Centre-justify each line.
   .El
   .Pp
   The type must be provided first.
   Secondary arguments are as follows:
   .Bl -tag -width 12n -offset indent
   .It Fl offset Ar val
   Offset by the value of
   .Ar val ,
   which is interpreted as one of the following, specified in order:
   .Bl -item
   .It
   As one of the pre-defined strings
   .Ar indent ,
   the width of standard indentation;
   .Ar indent-two ,
   twice
   .Ar indent ;
   .Ar left ,
   which has no effect;
   .Ar right ,
   which justifies to the right margin; and
   .Ar center ,
   which aligns around an imagined centre axis.
   .It
   As a precalculated width for a named macro.
   The most popular is the imaginary macro
   .Ar \&Ds ,
   which resolves to
   .Ar 6n .
   .It
   As a scaling unit following the syntax described in
   .Sx Scaling Widths .
   .It
   As the calculated string length of the opaque string.
   .El
   .Pp
   If not provided an argument, it will be ignored.
   .It Fl compact
   Do not assert a vertical space before the block.
   .El
   .Pp
   Examples:
   .Bd -literal -offset indent
   \&.Bd \-unfilled \-offset two-indent \-compact
      Hello       world.
   \&.Ed
   .Ed
   .Pp
   See also
   .Sx \&D1
   and
   .Sx \&Dl .
   .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
   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
   Begins a list composed of one or more list entries.
   Its syntax is as follows:
   .Bd -ragged -offset indent
   .Pf \. Sx \&Bl
   .Fl type
   .Op Fl width Ar val
   .Op Fl offset Ar val
   .Op Fl compact
   .Op HEAD ...
   .Ed
   .Pp
   A list is associated with a type, which is a required argument.
   Other arguments are
   .Fl width ,
   defined per-type as accepting a literal or
   .Sx Scaling Widths
   value;
   .Fl offset ,
   also accepting a literal or
   .Sx Scaling Widths
   value setting the list's global offset; and
   .Fl compact ,
   suppressing the default vertical space printed before each list entry.
   A list entry is specified by the
   .Sx \&It
   macro, which consists of a head and optional body (depending on the list
   type).
   A list must specify one of the following list types:
   .Bl -tag -width 12n -offset indent
   .It Fl bullet
   A list offset by a bullet.
   The head of list entries must be empty.
   List entry bodies are positioned after the bullet.
   The
   .Fl width
   argument varies the width of list bodies' left-margins.
   .It Fl column
   A columnated list.
   The
   .Fl width
   argument has no effect.
   The number of columns is specified as parameters to the
   .Sx \&Bl
   macro.
   These dictate the width of columns either as
   .Sx Scaling Widths
   or literal text.
   If the initial macro of a
   .Fl column
   list is not an
   .Sx \&It ,
   an
   .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
   Begins a block enclosed by square brackets.
   Does not have any head arguments.
   .Pp
   Examples:
   .Bd -literal -offset indent
   \&.Bo 1 ,
   \&.Dv BUFSIZ \&Bc
   .Ed
   .Pp
   See also
   .Sx \&Bq .
   .Ss \&Bq
   Encloses its arguments in square brackets.
   .Pp
   Examples:
   .D1 \&.Bq 1 , \&Dv BUFSIZ
   .Pp
   .Em Remarks :
   this macro is sometimes abused to emulate optional arguments for
   commands; the correct macros to use for this purpose are
   .Sx \&Op ,
   .Sx \&Oo ,
   and
   .Sx \&Oc .
   .Pp
   See also
   .Sx \&Bo .
   .Ss \&Brc
   Closes a
   .Sx \&Bro
   block.
   Does not have any tail arguments.
   .Ss \&Bro
   Begins a block enclosed by curly braces.
   Does not have any head arguments.
   .Pp
   Examples:
   .Bd -literal -offset indent
   \&.Bro 1 , ... ,
   \&.Va n \&Brc
   .Ed
   .Pp
   See also
   .Sx \&Brq .
   .Ss \&Brq
   Encloses its arguments in curly braces.
   .Pp
   Examples:
   .D1 \&.Brq 1 , ... , \&Va n
   .Pp
   See also
   .Sx \&Bro .
   .Ss \&Bsx
   Format the BSD/OS version provided as an argument, or a default value if
   no argument is provided.
   .Pp
   Examples:
   .D1 \&.Bsx 1.0
   .D1 \&.Bsx
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .Ss \&Bt
   Prints
   .Dq is currently in beta test.
   .Ss \&Bx
   Format the BSD version provided as an argument, or a default value if no
   argument is provided.
   .Pp
   Examples:
   .D1 \&.Bx 4.4
   .D1 \&.Bx
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .Ss \&Cd
   Configuration declaration.
   This denotes strings accepted by
   .Xr config 8 .
   .Pp
   Examples:
   .D1 \&.Cd device le0 at scode?
   .Pp
   .Em Remarks :
   this macro is commonly abused by using quoted literals to retain
   whitespace and align consecutive
   .Sx \&Cd
   declarations.
   This practise is discouraged.
   .Ss \&Cm
   Command modifiers.
   Useful when specifying configuration options or keys.
   .Pp
   Examples:
   .D1 \&.Cm ControlPath
   .D1 \&.Cm ControlMaster
   .Pp
   See also
   .Sx \&Fl .
   .Ss \&D1
   One-line indented display.
   This is formatted by the default rules and is useful for simple indented
   statements.
   It is followed by a newline.
   .Pp
   Examples:
   .D1 \&.D1 \&Fl abcdefgh
   .Pp
   See also
   .Sx \&Bd
   and
   .Sx \&Dl .
   .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
   Closes a
   .Sx \&Do
   block.
   Does not have any tail arguments.
   .Ss \&Dd
   Document date.
   This is the mandatory first macro of any
   .Nm
   manual.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Dd Cm date
   .Pp
   The
   .Cm date
   field may be either
   .Ar $\&Mdocdate$ ,
   which signifies the current manual revision date dictated by
   .Xr cvs 1 ,
   or instead a valid canonical date as specified by
   .Sx Dates .
   If a date does not conform, the current date is used instead.
   .Pp
   Examples:
   .D1 \&.Dd $\&Mdocdate$
   .D1 \&.Dd $\&Mdocdate: July 21 2007$
   .D1 \&.Dd July 21, 2007
   .Pp
   See also
   .Sx \&Dt
   and
   .Sx \&Os .
   .Ss \&Dl
   One-line intended display.
   This is formatted as literal text and is useful for commands and
   invocations.
   It is followed by a newline.
   .Pp
   Examples:
   .D1 \&.Dl % mandoc mdoc.7 | less
   .Pp
   See also
   .Sx \&Bd
   and
   .Sx \&D1 .
   .Ss \&Do
   Begins a block enclosed by double quotes.
   Does not have any head arguments.
   .Pp
   Examples:
   .D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot
   .Pp
   See also
   .Sx \&Dq .
   .Ss \&Dq
   Encloses its arguments in
   .Dq typographic
   double-quotes.
   .Pp
   Examples:
   .Bd -literal -offset indent -compact
   \&.Dq April is the cruellest month
   \e(em T.S. Eliot
   .Ed
   .Pp
   See also
   .Sx \&Qq ,
   .Sx \&Sq ,
   and
   .Sx \&Do .
   .Ss \&Dt
   Document title.
   This is the mandatory second macro of any
   .Nm
   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
   Its arguments are as follows:
   .Bl -tag -width Ds -offset Ds
   .It Cm title
   The document's title (name), defaulting to
   .Dq UNKNOWN
   if unspecified.
   It should be capitalised.
   .It Cm section
   The manual section.
   This may be one of
   .Ar 1
   .Pq utilities ,
   .Ar 2
   .Pq system calls ,
   .Ar 3
   .Pq libraries ,
   .Ar 3p
   .Pq Perl libraries ,
   .Ar 4
   .Pq devices ,
   .Ar 5
   .Pq file formats ,
   .Ar 6
   .Pq games ,
   .Ar 7
   .Pq miscellaneous ,
   .Ar 8
   .Pq system utilities ,
   .Ar 9
   .Pq kernel functions ,
   .Ar X11
   .Pq X Window System ,
   .Ar X11R6
   .Pq X Window System ,
   .Ar unass
   .Pq unassociated ,
   .Ar local
   .Pq local system ,
   .Ar draft
   .Pq draft manual ,
   or
   .Ar paper
   .Pq paper .
   It should correspond to the manual's filename suffix and defaults to
   .Dq 1
   if unspecified.
   .It Cm volume
   This overrides the volume inferred from
   .Ar section .
   This field is optional, and if specified, must be one of
   .Ar USD
   .Pq users' supplementary documents ,
   .Ar PS1
   .Pq programmers' supplementary documents ,
   .Ar AMD
   .Pq administrators' supplementary documents ,
   .Ar SMM
   .Pq system managers' manuals ,
   .Ar URM
   .Pq users' reference manuals ,
   .Ar PRM
   .Pq programmers' reference manuals ,
   .Ar KM
   .Pq kernel manuals ,
   .Ar IND
   .Pq master index ,
   .Ar MMI
   .Pq master index ,
   .Ar LOCAL
   .Pq local manuals ,
   .Ar LOC
   .Pq local manuals ,
   or
   .Ar CON
   .Pq contributed manuals .
   .It Cm arch
   This specifies a specific relevant architecture.
   If
   .Cm volume
   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
   .Ar alpha ,
   .Ar amd64 ,
   .Ar amiga ,
   .Ar arc ,
   .Ar arm ,
   .Ar armish ,
   .Ar aviion ,
   .Ar hp300 ,
   .Ar hppa ,
   .Ar hppa64 ,
   .Ar i386 ,
   .Ar landisk ,
   .Ar loongson ,
   .Ar luna88k ,
   .Ar mac68k ,
   .Ar macppc ,
   .Ar mvme68k ,
   .Ar mvme88k ,
   .Ar mvmeppc ,
   .Ar pmax ,
   .Ar sgi ,
   .Ar socppc ,
   .Ar sparc ,
   .Ar sparc64 ,
   .Ar sun3 ,
   .Ar vax ,
   or
   .Ar zaurus .
   .El
   .Pp
   Examples:
   .D1 \&.Dt FOO 1
   .D1 \&.Dt FOO 4 KM
   .D1 \&.Dt FOO 9 i386
   .Pp
   See also
   .Sx \&Dd
   and
   .Sx \&Os .
   .Ss \&Dv
   Defined variables such as preprocessor constants.
   .Pp
   Examples:
   .D1 \&.Dv BUFSIZ
   .D1 \&.Dv STDOUT_FILENO
   .Pp
   See also
   .Sx \&Er .
   .Ss \&Dx
   Format the DragonFly BSD version provided as an argument, or a default
   value if no argument is provided.
   .Pp
   Examples:
   .D1 \&.Dx 2.4.1
   .D1 \&.Dx
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .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
   End a display context started by
   .Sx \&Bd .
   .Ss \&Ef
   Ends a font mode context started by
   .Sx \&Bf .
   .Ss \&Ek
   Ends a keep context started by
   .Sx \&Bk .
   .Ss \&El
   Ends a list context started by
   .Sx \&Bl .
   .Pp
   See also
   .Sx \&Bl
   and
   .Sx \&It .
   .Ss \&Em
   Denotes text that should be emphasised.
   Note that this is a presentation term and should not be used for
   stylistically decorating technical terms.
   .Pp
   Examples:
   .D1 \&.Em Warnings!
   .D1 \&.Em Remarks :
   .Pp
   See also
   .Sx \&Bf ,
   .Sx \&Sy ,
   and
   .Sx \&Li .
   .Ss \&En
   This macro is obsolete and not implemented.
   .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
   Display error constants.
   .Pp
   Examples:
   .D1 \&.Er EPERM
   .D1 \&.Er ENOENT
   .Pp
   See also
   .Sx \&Dv .
   .Ss \&Es
   This macro is obsolete and not implemented.
   .Ss \&Ev
   Environmental variables such as those specified in
   .Xr environ 7 .
   .Pp
   Examples:
   .D1 \&.Ev DISPLAY
   .D1 \&.Ev PATH
   .Ss \&Ex
   Inserts text regarding a utility's exit value.
   This macro must consist of the
   .Fl std
   argument followed by an optional
   .Ar utility .
   If
   .Ar utility
   is not provided, the document's name as stipulated in
   .Sx \&Nm
   is provided.
   .Pp
   See also
   .Sx \&Rv .
   .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
   Ends a function context started by
   .Sx \&Fo .
   .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
   Command-line flag.
   Used when listing arguments to command-line utilities.
   Prints a fixed-width hyphen
   .Sq \-
   directly followed by each argument.
   If no arguments are provided, a hyphen is printed followed by a space.
   If the argument is a macro, a hyphen is prefixed to the subsequent macro
   output.
   .Pp
   Examples:
   .D1 \&.Fl a b c
   .D1 \&.Fl \&Pf a b
   .D1 \&.Fl
   .D1 \&.Op \&Fl o \&Ns \&Ar file
   .Pp
   See also
   .Sx \&Cm .
   .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
   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
   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
   Format the FreeBSD version provided as an argument, or a default value
   if no argument is provided.
   .Pp
   Examples:
   .D1 \&.Fx 7.1
   .D1 \&.Fx
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Nx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .Ss \&Hf
   This macro is obsolete and not implemented.
   .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
   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
   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
   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
   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
   Format a hyperlink.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Lk Cm uri Op Cm name
   .Pp
   Examples:
   .D1 \&.Lk http://bsd.lv "The BSD.lv Project"
   .D1 \&.Lk http://bsd.lv
   .Pp
   See also
   .Sx \&Mt .
   .Ss \&Lp
   Synonym for
   .Sx \&Pp .
   .Ss \&Ms
   Display a mathematical symbol.
   .Pp
   Examples:
   .D1 \&.Ms sigma
   .D1 \&.Ms aleph
   .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
   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
   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
   A
   .Dq noop
   macro used to terminate prior macro contexts.
   .Pp
   Examples:
   .D1 \&.Sx \&Fl ab \&No cd \&Fl ef
   .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
   Format the NetBSD version provided as an argument, or a default value if
   no argument is provided.
   .Pp
   Examples:
   .D1 \&.Nx 5.01
   .D1 \&.Nx
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Ox ,
   and
   .Sx \&Ux .
   .Ss \&Oc
   Closes multi-line
   .Sx \&Oo
   context.
   .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
   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
   Document operating system version.
   This is the mandatory third macro of
   any
   .Nm
   file.
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Os Op Cm system
   .Pp
   The optional
   .Cm system
   parameter specifies the relevant operating system or environment.
   Left unspecified, it defaults to the local operating system version.
   This is the suggested form.
   .Pp
   Examples:
   .D1 \&.Os
   .D1 \&.Os KTH/CSC/TCS
   .D1 \&.Os BSD 4.3
   .Pp
   See also
   .Sx \&Dd
   and
   .Sx \&Dt .
   .Ss \&Ot
   Unknown usage.
   .Pp
   .Em Remarks :
   this macro has been deprecated.
   .Ss \&Ox
   Format the OpenBSD version provided as an argument, or a default value
   if no argument is provided.
   .Pp
   Examples:
   .D1 \&.Ox 4.5
   .D1 \&.Ox
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   and
   .Sx \&Ux .
   .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
   Close parenthesised context opened by
   .Sx \&Po .
   .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
   Multi-line version of
   .Sx \&Pq .
   .Ss \&Pp
   Break a paragraph.
   This will assert vertical space between prior and subsequent macros
   and/or text.
   .Ss \&Pq
   Parenthesised enclosure.
   .Pp
   See also
   .Sx \&Po .
   .Ss \&Qc
   Close quoted context opened by
   .Sx \&Qo .
   .Ss \&Ql
   Format a single-quoted literal.
   See also
   .Sx \&Qq
   and
   .Sx \&Sq .
   .Ss \&Qo
   Multi-line version of
   .Sx \&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
   Closes a
   .Sx \&Rs
   block.
   Does not have any tail arguments.
   .Ss \&Rs
   Begins a bibliographic
   .Pq Dq reference
   block.
   Does not have any head arguments.
   The block macro may only contain
   .Sx \&%A ,
   .Sx \&%B ,
   .Sx \&%C ,
   .Sx \&%D ,
   .Sx \&%I ,
   .Sx \&%J ,
   .Sx \&%N ,
   .Sx \&%O ,
   .Sx \&%P ,
   .Sx \&%Q ,
   .Sx \&%R ,
   .Sx \&%T ,
   .Sx \&%U ,
   and
   .Sx \&%V
   child macros (at least one must be specified).
   .Pp
   Examples:
   .Bd -literal -offset indent -compact
   \&.Rs
   \&.%A J. E. Hopcroft
   \&.%A J. D. Ullman
   \&.%B Introduction to Automata Theory, Languages, and Computation
   \&.%I Addison-Wesley
   \&.%C Reading, Massachusettes
   \&.%D 1979
   \&.Re
   .Ed
   .Pp
   If an
   .Sx \&Rs
   block is used within a SEE ALSO section, a vertical space is asserted
   before the rendered output, else the block continues on the current
   line.
   .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
   Close single-quoted context opened by
   .Sx \&So .
   .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
   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
   Multi-line version of
   .Sx \&Sq .
   .Ss \&Sq
   Encloses its arguments in
   .Dq typewriter
   single-quotes.
   .Pp
   See also
   .Sx \&Dq ,
   .Sx \&Qq ,
   and
   .Sx \&So .
   .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
   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
   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
   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
   Format a tradename.
   .Pp
   Examples:
   .D1 \&.Tn IBM
   .Ss \&Ud
   Prints out
   .Dq currently under development.
   .Ss \&Ux
   Format the UNIX name.
   Accepts no argument.
   .Pp
   Examples:
   .D1 \&.Ux
   .Pp
   See also
   .Sx \&At ,
   .Sx \&Bsx ,
   .Sx \&Bx ,
   .Sx \&Dx ,
   .Sx \&Fx ,
   .Sx \&Nx ,
   and
   .Sx \&Ox .
   .Ss \&Va
   A variable name.
   .Pp
   Examples:
   .D1 \&.Va foo
   .D1 \&.Va const char *bar ;
   .Ss \&Vt
   A variable type.
   This is also used for indicating global variables in the
   .Em SYNOPSIS
   section, in which case a variable name is also specified.
   Note that it accepts
   .Sx Block partial-implicit
   syntax when invoked as the first macro in the
   .Em SYNOPSIS
   section, else it accepts ordinary
   .Sx In-line
   syntax.
   .Pp
   Note that this should not be confused with
   .Sx \&Ft ,
   which is used for function return types.
   .Pp
   Examples:
   .D1 \&.Vt unsigned char
   .D1 \&.Vt extern const char * const sys_signame[] \&;
   .Pp
   See also
   .Sx MANUAL STRUCTURE
   and
   .Sx \&Va .
   .Ss \&Xc
   Close a scope opened by
   .Sx \&Xo .
   .Ss \&Xo
   Open an extension scope.
   This macro originally existed to extend the 9-argument limit of troff;
   since this limit has been lifted, the macro has been deprecated.
   .Ss \&Xr
   Link to another manual
   .Pq Qq cross-reference .
   Its syntax is as follows:
   .Pp
   .D1 Pf \. Sx \&Xr Cm name section
   .Pp
   The
   .Cm name
   and
   .Cm section
   are the name and section of the linked manual.
   If
   .Cm section
   is followed by non-punctuation, an
   .Sx \&Ns
   is inserted into the token stream.
   This behaviour is for compatibility with
   .Xr groff 1 .
   .Pp
   Examples:
   .D1 \&.Xr mandoc 1
   .D1 \&.Xr mandoc 1 \&;
   .D1 \&.Xr mandoc 1 \&Ns s behaviour
   .Ss \&br
   .Ss \&sp
   .Sh COMPATIBILITY
   This section documents compatibility between mandoc and other other
   troff implementations, at this time limited to GNU troff
   .Pq Qq groff .
   The term
   .Qq historic groff
   refers to groff versions before the
   .Pa doc.tmac
   file re-write
   .Pq somewhere between 1.15 and 1.19 .
   .Pp
   Heirloom troff, the other significant troff implementation accepting
   \-mdoc, is similar to historic groff.
   .Pp
   .Bl -dash -compact
   .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
   .Sq \e\."
   is no longer accepted.
   .It
   In groff, the
   .Sx \&Pa
   macro does not format its arguments when used in the FILES section under
   certain list types.
   mandoc does.
   .It
   Historic groff does not print a dash for empty
   .Sx \&Fl
   arguments.
   mandoc and newer groff implementations do.
   .It
   groff behaves irregularly when specifying
   .Sq \ef
   .Sx Text Decoration
   within line-macro scopes.
   mandoc follows a consistent system.
   .It
   In mandoc, negative scaling units are truncated to zero; groff would
   move to prior lines.
   Furthermore, the
   .Sq f
   scaling unit, while accepted, is rendered as the default unit.
   .It
   In quoted literals, groff allowed pair-wise double-quotes to produce a
   standalone double-quote in formatted output.
   This idiosyncratic behaviour is not applicable in mandoc.
   .It
   Display offsets
   .Sx \&Bd
   .Fl offset Ar center
   and
   .Fl offset Ar right
   are disregarded in mandoc.
   Furthermore, troff specifies a
   .Fl file Ar file
   argument that is not supported in mandoc.
   Lastly, since text is not right-justified in mandoc (or even groff),
   .Fl ragged
   and
   .Fl filled
   are aliases, as are
   .Fl literal
   and
   .Fl unfilled .
   .It
   Historic groff has many un-callable macros.
   Most of these (excluding some block-level macros) are now callable.
   .It
   The vertical bar
   .Sq \(ba
   made historic groff
   .Qq go orbital
   but has been a proper delimiter since then.
   .It
   .Sx \&It Fl nested
   is assumed for all lists (it wasn't in historic groff): any list may be
   nested and
   .Fl enum
   lists will restart the sequence only for the sub-list.
   .It
   Some manuals use
   .Sx \&Li
   incorrectly by following it with a reserved character and expecting the
   delimiter to render.
   This is not supported in mandoc.
   .It
   In groff, the
   .Sx \&Cd ,
   .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
   .Sh SEE ALSO
   .Xr mandoc 1 ,
   .Xr mandoc_char 7
   .Sh AUTHORS
   The
   .Nm
   reference was written by
   .An Kristaps Dzonsons Aq kristaps@bsd.lv .
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