===================================================================
RCS file: /cvs/mandoc/man.7,v
retrieving revision 1.62
retrieving revision 1.146
diff -u -p -r1.62 -r1.146
--- mandoc/man.7	2010/04/13 05:26:49	1.62
+++ mandoc/man.7	2020/10/14 14:22:54	1.146
@@ -1,6 +1,9 @@
-.\"	$Id: man.7,v 1.62 2010/04/13 05:26:49 kristaps Exp $
+.\"	$Id: man.7,v 1.146 2020/10/14 14:22:54 schwarze Exp $
 .\"
-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2011-2015, 2017-2020 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2017 Anthony Bentley <bentley@openbsd.org>
+.\" Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -14,502 +17,123 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: April 13 2010 $
+.Dd $Mdocdate: October 14 2020 $
 .Dt MAN 7
 .Os
 .Sh NAME
 .Nm man
-.Nd man language reference
+.Nd legacy formatting language for manual pages
 .Sh DESCRIPTION
 The
 .Nm man
-language was historically used to format
-.Ux
-manuals.  This reference document describes its syntax, structure, and
-usage.
-.Pp
-.Bf -emphasis
-Do not use
-.Nm
-to write your manuals.
-.Ef
+language was the standard formatting language for
+.At
+manual pages from 1979 to 1989.
+Do not use it to write new manual pages: it is a purely presentational
+language and lacks support for semantic markup.
 Use the
 .Xr mdoc 7
 language, instead.
 .Pp
-An
+In a
 .Nm
-document follows simple rules:  lines beginning with the control
-character
+document, lines beginning with the control character
 .Sq \&.
-are parsed for macros.  Other lines are interpreted within the scope of
-prior macros:
+are called
+.Dq macro lines .
+The first word is the macro name.
+It usually consists of two capital letters.
+For a list of portable macros, see
+.Sx MACRO OVERVIEW .
+The words following the macro name are arguments to the macro.
+.Pp
+Lines not beginning with the control character are called
+.Dq text lines .
+They provide free-form text to be printed; the formatting of the text
+depends on the respective processing context:
 .Bd -literal -offset indent
 \&.SH Macro lines change control state.
-Other lines are interpreted within the current state.
+Text lines are interpreted within the current state.
 .Ed
-.Sh INPUT ENCODING
-.Nm
-documents may contain only graphable 7-bit ASCII characters, the
-space character, and the tabs character.  All manuals must have
-.Ux
-line termination.
 .Pp
-Blank lines are acceptable; where found, the output will assert a
-vertical space.
-.Ss Comments
-Text following a
-.Sq \e\*" ,
-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" ,
-is also ignored.  Macro lines with only a control character and
-optionally whitespace are stripped from input.
-.Ss Special Characters
-Special characters may occur in both macro and free-form lines.
-Sequences begin with the escape character
-.Sq \e
-followed by either an open-parenthesis
-.Sq \&(
-for two-character sequences; an open-bracket
-.Sq \&[
-for n-character sequences (terminated at a close-bracket
-.Sq \&] ) ;
-or a single one-character sequence.  See
-.Xr mandoc_char 7
-for a complete list.  Examples include
-.Sq \e(em
-.Pq em-dash
+Many aspects of the basic syntax of the
+.Nm
+language are based on the
+.Xr roff 7
+language; see the
+.Em LANGUAGE SYNTAX
 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):
+.Em MACRO SYNTAX
+sections in the
+.Xr roff 7
+manual for details, in particular regarding
+comments, escape sequences, whitespace, and quoting.
 .Pp
-.D1 \efBbold\efR \efIitalic\efP
-.Pp
-A numerical representation 3, 2, or 1 (bold, italic, and Roman,
-respectively) may be used instead.  A text decoration is only valid, if
-specified in free-form text, until the next macro invocation; if
-specified within a macro, it's only valid until the macro closes scope.
-Note that macros like
-.Sx \&BR
-open and close a font scope with each argument.
-.Pp
-Text may also be sized with the
-.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
-Both
-.Sq \es
-and
-.Sq \ef
-attributes are forgotten when entering or exiting a macro block.
-.Ss Whitespace
-Unless specifically escaped, consecutive blocks of whitespace are pruned
-from input.  These are later re-added, if applicable, by a front-end
-utility such as
-.Xr mandoc 1 .
-.Ss Dates
-The
-.Sx \&TH
-macro is the only
-.Nm
-macro that requires a date.  The form for this date is the ISO-8601
-standard
-.Cm YYYY-MM-DD .
-.Ss Scaling Widths
-Many macros support scaled widths for their arguments, such as
-stipulating a two-inch paragraph indentation with the following:
-.Bd -literal -offset indent
-\&.HP 2i
-.Ed
-.Pp
-The syntax for scaled widths is
-.Sq Li [+-]?[0-9]*.[0-9]*[:unit:]? ,
-where a decimal must be preceded or proceeded by at least one digit.
-Negative numbers, while accepted, are truncated to zero.  The following
-scaling units are accepted:
-.Pp
-.Bl -tag -width Ds -offset indent -compact
-.It c
-centimetre
-.It i
-inch
-.It P
-pica (~1/6 inch)
-.It p
-point (~1/72 inch)
-.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
-.Pp
-Using anything other than
-.Sq m ,
-.Sq n ,
-.Sq u ,
-or
-.Sq v
-is necessarily non-portable across output media.
-.Pp
-If a scaling unit is not provided, the numerical value is interpreted
-under the default rules of
-.Sq v
-for vertical spaces and
-.Sq u
-for horizontal ones.
-.Em Note :
-this differs from
-.Xr mdoc 7 ,
-which, if a unit is not provided, will instead interpret the string as
-literal text.
-.Sh MANUAL STRUCTURE
 Each
 .Nm
-document must contain contains at least the
-.Sx \&TH
-macro describing the document's section and title.  It may occur
-anywhere in the document, although conventionally, it appears as the
-first macro.
-.Pp
-Beyond
-.Sx \&TH ,
-at least one macro or text node must appear in the document.  Documents
-are generally structured as follows:
+document starts with the
+.Ic TH
+macro specifying the document's name and section, followed by the
+.Sx NAME
+section formatted as follows:
 .Bd -literal -offset indent
-\&.TH FOO 1 2009-10-10
-\&.
+\&.TH PROGNAME 1 1979-01-10
 \&.SH NAME
-\efBfoo\efR \e(en a description goes here
-\&.\e\*q The next is for sections 2 & 3 only.
-\&.\e\*q .SH LIBRARY
-\&.
-\&.SH SYNOPSIS
-\efBfoo\efR [\efB\e-options\efR] arguments...
-\&.
-\&.SH DESCRIPTION
-The \efBfoo\efR utility processes files...
-\&.
-\&.\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 .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 .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 .BR foo ( 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
+\efBprogname\efR \e(en one line about what it does
 .Ed
-.Pp
-The sections in a
-.Nm
-document are conventionally ordered as they appear above.  Sections
-should be composed as follows:
-.Bl -ohang -offset indent
-.It Em NAME
-The name(s) and a short description of the documented material.  The
-syntax for this is generally as follows:
-.Pp
-.D1 \efBname\efR \e(en description
-.It Em LIBRARY
-The name of the library containing the documented material, which is
-assumed to be a function in a section 2 or 3 manual.  For functions in
-the C library, this may be as follows:
-.Pp
-.D1 Standard C Library (libc, -lc)
-.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:
-.Pp
-.D1 \efBname\efR [-\efBab\efR] [-\efBc\efR\efIarg\efR] \efBpath\efR...
-.Pp
-For the second, function calls (sections 2, 3, 9):
-.Pp
-.D1 \&.B char *name(char *\efIarg\efR);
-.Pp
-And for the third, configurations (section 4):
-.Pp
-.D1 \&.B name* at cardbus ? function ?
-.Pp
-Manuals not in these sections generally don't need a
-.Em SYNOPSIS .
-.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).
-.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 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.
-.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.
-.It Em ENVIRONMENT
-Documents any usages of environment variables, e.g.,
-.Xr environ 7 .
-.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.).
-.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.
-.It Em ERRORS
-Documents error handling in sections 2, 3, and 9.
-.It Em SEE ALSO
-References other manuals with related topics.  This section should exist
-for most manuals.
-.Pp
-.D1 \&.BR bar \&( 1 \&),
-.Pp
-Cross-references should conventionally be ordered
-first by section, then alphabetically.
-.It Em STANDARDS
-References any standards implemented or used, such as
-.Pp
-.D1 IEEE Std 1003.2 (\e(lqPOSIX.2\e(rq)
-.Pp
-If not adhering to any standards, the
-.Em HISTORY
-section should be used.
-.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.
-.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.
+.Sh MACRO OVERVIEW
+This overview is sorted such that macros of similar purpose are listed
+together.
+Deprecated and non-portable macros are not included in the overview,
+but can be found in the alphabetical reference below.
+.Ss Page header and footer meta-data
+.Bl -column "RS, RE" description
+.It Ic TH Ta set the title: Ar name section date Op Ar source Op Ar volume
+.It Ic AT Ta display AT&T UNIX version in the page footer (<= 1 argument)
+.It Ic UC Ta display BSD version in the page footer (<= 1 argument)
 .El
-.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.  The
-.Sq \(aq
-macro control character is also accepted.  An arbitrary amount of
-whitespace (spaces or tabs) may sit between the control character and
-the macro name.  Thus, the following are equivalent:
-.Bd -literal -offset indent
-\&.PP
-\&.\ \ \ PP
-.Ed
-.Pp
-The
-.Nm
-macros are classified by scope: line scope or block scope.  Line
-macros are only scoped to the current line (and, in some situations,
-the subsequent line).  Block macros are scoped to the current line and
-subsequent lines until closed by another block macro.
-.Ss Line Macros
-Line macros are generally scoped to the current line, with the body
-consisting of zero or more arguments.  If a macro is scoped to the next
-line and the line arguments are empty, the next line, which must be
-text, is used instead.  Thus:
-.Bd -literal -offset indent
-\&.I
-foo
-.Ed
-.Pp
-is equivalent to
-.Sq \&.I foo .
-If next-line macros are invoked consecutively, only the last is used.
-If a next-line macro is followed by a non-next-line macro, an error is
-raised (unless in the case of
-.Sx \&br ,
-.Sx \&sp ,
-or
-.Sx \&na ) .
-.Pp
-The syntax is as follows:
-.Bd -literal -offset indent
-\&.YO \(lBbody...\(rB
-\(lBbody...\(rB
-.Ed
-.Pp
-.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX"
-.It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
-.It Sx \&B   Ta    n         Ta    next-line Ta    \&
-.It Sx \&BI  Ta    n         Ta    current   Ta    \&
-.It Sx \&BR  Ta    n         Ta    current   Ta    \&
-.It Sx \&DT  Ta    0         Ta    current   Ta    \&
-.It Sx \&I   Ta    n         Ta    next-line Ta    \&
-.It Sx \&IB  Ta    n         Ta    current   Ta    \&
-.It Sx \&IR  Ta    n         Ta    current   Ta    \&
-.\" .It Sx \&PD  Ta    n         Ta    current   Ta    compat
-.It Sx \&R   Ta    n         Ta    next-line Ta    \&
-.It Sx \&RB  Ta    n         Ta    current   Ta    \&
-.It Sx \&RI  Ta    n         Ta    current   Ta    \&
-.It Sx \&SB  Ta    n         Ta    next-line Ta    \&
-.It Sx \&SM  Ta    n         Ta    next-line Ta    \&
-.It Sx \&TH  Ta    >1, <6    Ta    current   Ta    \&
-.\" .It Sx \&UC  Ta    n         Ta    current   Ta    compat
-.It Sx \&br  Ta    0         Ta    current   Ta    compat
-.It Sx \&fi  Ta    0         Ta    current   Ta    compat
-.It Sx \&i   Ta    n         Ta    current   Ta    compat
-.It Sx \&na  Ta    0         Ta    current   Ta    compat
-.It Sx \&nf  Ta    0         Ta    current   Ta    compat
-.It Sx \&r   Ta    0         Ta    current   Ta    compat
-.It Sx \&sp  Ta    1         Ta    current   Ta    compat
-.\" .It Sx \&Sp  Ta    0         Ta    current   Ta    compat
-.\" .It Sx \&Vb  Ta    <1        Ta    current   Ta    compat
-.\" .It Sx \&Ve  Ta    0         Ta    current   Ta    compat
+.Ss Sections and paragraphs
+.Bl -column "RS, RE" description
+.It Ic SH Ta section header (one line)
+.It Ic SS Ta subsection header (one line)
+.It Ic PP Ta start an undecorated paragraph (no arguments)
+.It Ic RS , RE Ta reset the left margin: Op Ar width
+.It Ic IP Ta indented paragraph: Op Ar head Op Ar width
+.It Ic TP Ta tagged paragraph: Op Ar width
+.It Ic PD Ta set vertical paragraph distance: Op Ar height
+.It Ic in Ta additional indent: Op Ar width
 .El
-.Pp
-Macros marked as
-.Qq compat
-are included for compatibility with the significant corpus of existing
-manuals that mix dialects of roff.  These macros should not be used for
-portable
-.Nm
-manuals.
-.Ss Block Macros
-Block macros are comprised of a head and body.  Like for in-line macros,
-the head is scoped to the current line and, in one circumstance, the
-next line (the next-line stipulations as in
-.Sx Line Macros
-apply here as well).
-.Pp
-The syntax is as follows:
-.Bd -literal -offset indent
-\&.YO \(lBhead...\(rB
-\(lBhead...\(rB
-\(lBbody...\(rB
-.Ed
-.Pp
-The closure of body scope may be to the section, where a macro is closed
-by
-.Sx \&SH ;
-sub-section, closed by a section or
-.Sx \&SS ;
-part, closed by a section, sub-section, or
-.Sx \&RE ;
-or paragraph, closed by a section, sub-section, part,
-.Sx \&HP ,
-.Sx \&IP ,
-.Sx \&LP ,
-.Sx \&P ,
-.Sx \&PP ,
-or
-.Sx \&TP .
-No closure refers to an explicit block closing macro.
-.Pp
-As a rule, block macros may not be nested; thus, calling a block macro
-while another block macro scope is open, and the open scope is not
-implicitly closed, is syntactically incorrect.
-.Pp
-.Bl -column -compact -offset indent "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX"
-.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope  Ta Em Notes
-.It Sx \&HP  Ta    <2        Ta    current    Ta    paragraph   Ta    \&
-.It Sx \&IP  Ta    <3        Ta    current    Ta    paragraph   Ta    \&
-.It Sx \&LP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
-.It Sx \&P   Ta    0         Ta    current    Ta    paragraph   Ta    \&
-.It Sx \&PP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
-.It Sx \&RE  Ta    0         Ta    current    Ta    none        Ta    compat
-.It Sx \&RS  Ta    1         Ta    current    Ta    part        Ta    compat
-.It Sx \&SH  Ta    >0        Ta    next-line  Ta    section     Ta    \&
-.It Sx \&SS  Ta    >0        Ta    next-line  Ta    sub-section Ta    \&
-.It Sx \&TP  Ta    n         Ta    next-line  Ta    paragraph   Ta    \&
+.Ss Physical markup
+.Bl -column "RS, RE" description
+.It Ic B Ta boldface font
+.It Ic I Ta italic font
+.It Ic SB Ta small boldface font
+.It Ic SM Ta small roman font
+.It Ic BI Ta alternate between boldface and italic fonts
+.It Ic BR Ta alternate between boldface and roman fonts
+.It Ic IB Ta alternate between italic and boldface fonts
+.It Ic IR Ta alternate between italic and roman fonts
+.It Ic RB Ta alternate between roman and boldface fonts
+.It Ic RI Ta alternate between roman and italic fonts
 .El
-.Pp
-Macros marked
-.Qq compat
-are as mentioned in
-.Sx Line Macros .
-.Pp
-If a block macro is next-line scoped, it may only be followed by in-line
-macros for decorating text.
-.Sh REFERENCE
+.Sh MACRO REFERENCE
 This section is a canonical reference to all macros, arranged
-alphabetically.  For the scoping of individual macros, see
+alphabetically.
+For the scoping of individual macros, see
 .Sx MACRO SYNTAX .
-.Ss \&B
+.Bl -tag -width 3n
+.It Ic AT
+Sets the volume for the footer for compatibility with man pages from
+.At
+releases.
+The optional arguments specify which release it is from.
+This macro is an extension that first appeared in
+.Bx 4.3 .
+.It Ic B
 Text is rendered in bold face.
-.Pp
-See also
-.Sx \&I ,
-.Sx \&R ,
-.Sx \&b ,
-.Sx \&i ,
-and
-.Sx \&r .
-.Ss \&BI
-Text is rendered alternately in bold face and italic.  Thus,
+.It Ic BI
+Text is rendered alternately in bold face and italic.
+Thus,
 .Sq .BI this word and that
 causes
 .Sq this
@@ -519,400 +143,490 @@ to render in bold face, while
 .Sq word
 and
 .Sq that
-render in italics.  Whitespace between arguments is omitted in output.
+render in italics.
+Whitespace between arguments is omitted in output.
 .Pp
-Examples:
+Example:
 .Pp
-.D1 \&.BI bold italic bold italic
-.Pp
-The output of this example will be emboldened
-.Dq bold
-and italicised
-.Dq italic ,
-with spaces stripped between arguments.
-.Pp
-See also
-.Sx \&IB ,
-.Sx \&BR ,
-.Sx \&RB ,
-.Sx \&RI ,
-and
-.Sx \&IR .
-.Ss \&BR
+.Dl \&.BI bold italic bold italic
+.It Ic BR
 Text is rendered alternately in bold face and roman (the default font).
 Whitespace between arguments is omitted in output.
-.Pp
-See
-.Sx \&BI
-for an equivalent example.
-.Pp
 See also
-.Sx \&BI ,
-.Sx \&IB ,
-.Sx \&RB ,
-.Sx \&RI ,
-and
-.Sx \&IR .
-.Ss \&DT
-Has no effect.  Included for compatibility.
-.Ss \&HP
+.Ic BI .
+.It Ic DT
+Restore the default tabulator positions.
+They are at intervals of 0.5 inches.
+This has no effect unless the tabulator positions were changed with the
+.Xr roff 7
+.Ic ta
+request.
+.It Ic EE
+This is a non-standard Version 9
+.At
+extension later adopted by GNU.
+In
+.Xr mandoc 1 ,
+it does the same as the
+.Xr roff 7
+.Ic fi
+request (switch to fill mode).
+.It Ic EX
+This is a non-standard Version 9
+.At
+extension later adopted by GNU.
+In
+.Xr mandoc 1 ,
+it does the same as the
+.Xr roff 7
+.Ic nf
+request (switch to no-fill mode).
+.It Ic HP
 Begin a paragraph whose initial output line is left-justified, but
 subsequent output lines are indented, with the following syntax:
-.Bd -filled -offset indent
-.Pf \. Sx \&HP
-.Op Cm width
-.Ed
 .Pp
+.D1 Pf . Ic HP Op Ar width
+.Pp
 The
-.Cm width
-argument must conform to
-.Sx Scaling Widths .
-If specified, it's saved for later paragraph left-margins; if unspecified, the
-saved or default width is used.
+.Ar width
+argument is a
+.Xr roff 7
+scaling width.
+If specified, it's saved for later paragraph left margins;
+if unspecified, the saved or default width is used.
 .Pp
-See also
-.Sx \&IP ,
-.Sx \&LP ,
-.Sx \&P ,
-.Sx \&PP ,
-and
-.Sx \&TP .
-.Ss \&I
+This macro is portable, but deprecated
+because it has no good representation in HTML output,
+usually ending up indistinguishable from
+.Ic PP .
+.It Ic I
 Text is rendered in italics.
-.Pp
+.It Ic IB
+Text is rendered alternately in italics and bold face.
+Whitespace between arguments is omitted in output.
 See also
-.Sx \&B ,
-.Sx \&R ,
-.Sx \&b ,
-.Sx \&i ,
-and
-.Sx \&r .
-.Ss \&IB
-Text is rendered alternately in italics and bold face.  Whitespace
-between arguments is omitted in output.
-.Pp
-See
-.Sx \&BI
-for an equivalent example.
-.Pp
-See also
-.Sx \&BI ,
-.Sx \&BR ,
-.Sx \&RB ,
-.Sx \&RI ,
-and
-.Sx \&IR .
-.Ss \&IP
+.Ic BI .
+.It Ic IP
 Begin an indented paragraph with the following syntax:
-.Bd -filled -offset indent
-.Pf \. Sx \&IP
-.Op Cm head Op Cm width
-.Ed
 .Pp
+.D1 Pf . Ic IP Op Ar head Op Ar width
+.Pp
 The
-.Cm width
-argument defines the width of the left margin and is defined by
-.Sx Scaling Widths ,
+.Ar width
+argument is a
+.Xr roff 7
+scaling width defining the left margin.
 It's saved for later paragraph left-margins; if unspecified, the saved or
 default width is used.
 .Pp
 The
-.Cm head
-argument is used as a leading term, flushed to the left margin.  This is
-useful for bulleted paragraphs and so on.
-.Pp
-See also
-.Sx \&HP ,
-.Sx \&LP ,
-.Sx \&P ,
-.Sx \&PP ,
-and
-.Sx \&TP .
-.Ss \&IR
+.Ar head
+argument is used as a leading term, flushed to the left margin.
+This is useful for bulleted paragraphs and so on.
+.It Ic IR
 Text is rendered alternately in italics and roman (the default font).
 Whitespace between arguments is omitted in output.
+See also
+.Ic BI .
+.It Ic LP
+A synonym for
+.Ic PP .
+.It Ic ME
+End a mailto block started with
+.Ic MT .
+This is a non-standard GNU extension.
+.It Ic MT
+Begin a mailto block.
+This is a non-standard GNU extension.
+It has the following syntax:
+.Bd -unfilled -offset indent
+.Pf . Ic MT Ar address
+link description to be shown
+.Pf . Ic ME
+.Ed
+.It Ic OP
+Optional command-line argument.
+This is a non-standard GNU extension.
+It has the following syntax:
 .Pp
-See
-.Sx \&BI
-for an equivalent example.
+.D1 Pf . Ic OP Ar key Op Ar value
 .Pp
-See also
-.Sx \&BI ,
-.Sx \&IB ,
-.Sx \&BR ,
-.Sx \&RB ,
-and
-.Sx \&RI .
-.Ss \&LP
-Begin an undecorated paragraph.  The scope of a paragraph is closed by a
-subsequent paragraph, sub-section, section, or end of file.  The saved
-paragraph left-margin width is re-set to the default.
+The
+.Ar key
+is usually a command-line flag and
+.Ar value
+its argument.
+.It Ic P
+This synonym for
+.Ic PP
+is an
+.At III
+extension later adopted by
+.Bx 4.3 .
+.It Ic PD
+Specify the vertical space to be inserted before each new paragraph.
+.br
+The syntax is as follows:
 .Pp
-See also
-.Sx \&HP ,
-.Sx \&IP ,
-.Sx \&P ,
-.Sx \&PP ,
-and
-.Sx \&TP .
-.Ss \&P
-Synonym for
-.Sx \&LP .
+.D1 Pf . Ic PD Op Ar height
 .Pp
-See also
-.Sx \&HP ,
-.Sx \&IP ,
-.Sx \&LP ,
-.Sx \&PP ,
-and
-.Sx \&TP .
-.Ss \&PP
-Synonym for
-.Sx \&LP .
+The
+.Ar height
+argument is a
+.Xr roff 7
+scaling width.
+It defaults to
+.Cm 1v .
+If the unit is omitted,
+.Cm v
+is assumed.
 .Pp
-See also
-.Sx \&HP ,
-.Sx \&IP ,
-.Sx \&LP ,
-.Sx \&P ,
+This macro affects the spacing before any subsequent instances of
+.Ic HP ,
+.Ic IP ,
+.Ic LP ,
+.Ic P ,
+.Ic PP ,
+.Ic SH ,
+.Ic SS ,
+.Ic SY ,
 and
-.Sx \&TP .
-.Ss \&R
-Text is rendered in roman (the default font).
-.Pp
-See also
-.Sx \&I ,
-.Sx \&B ,
-.Sx \&b ,
-.Sx \&i ,
-and
-.Sx \&r .
-.Ss \&RB
+.Ic TP .
+.It Ic PP
+Begin an undecorated paragraph.
+The scope of a paragraph is closed by a subsequent paragraph,
+sub-section, section, or end of file.
+The saved paragraph left-margin width is reset to the default.
+.It Ic RB
 Text is rendered alternately in roman (the default font) and bold face.
 Whitespace between arguments is omitted in output.
-.Pp
-See
-.Sx \&BI
-for an equivalent example.
-.Pp
 See also
-.Sx \&BI ,
-.Sx \&IB ,
-.Sx \&BR ,
-.Sx \&RI ,
-and
-.Sx \&IR .
-.Ss \&RE
+.Ic BI .
+.It Ic RE
 Explicitly close out the scope of a prior
-.Sx \&RS .
-.Ss \&RI
-Text is rendered alternately in roman (the default font) and italics.
-Whitespace between arguments is omitted in output.
+.Ic RS .
+The default left margin is restored to the state before that
+.Ic RS
+invocation.
 .Pp
-See
-.Sx \&BI
-for an equivalent example.
+The syntax is as follows:
 .Pp
+.D1 Pf . Ic RE Op Ar level
+.Pp
+Without an argument, the most recent
+.Ic RS
+block is closed out.
+If
+.Ar level
+is 1, all open
+.Ic RS
+blocks are closed out.
+Otherwise,
+.Ar level No \(mi 1
+nested
+.Ic RS
+blocks remain open.
+.It Ic RI
+Text is rendered alternately in roman (the default font) and italics.
+Whitespace between arguments is omitted in output.
 See also
-.Sx \&BI ,
-.Sx \&IB ,
-.Sx \&BR ,
-.Sx \&RB ,
-and
-.Sx \&IR .
-.Ss \&RS
-Begin a part setting the left margin.  The left margin controls the
-offset, following an initial indentation, to un-indented text such as
-that of
-.Sx \&PP .
+.Ic BI .
+.It Ic RS
+Temporarily reset the default left margin.
 This has the following syntax:
-.Bd -filled -offset indent
-.Pf \. Sx \&Rs
-.Op Cm width
-.Ed
 .Pp
+.D1 Pf . Ic RS Op Ar width
+.Pp
 The
-.Cm width
-argument must conform to
-.Sx Scaling Widths .
+.Ar width
+argument is a
+.Xr roff 7
+scaling width.
 If not specified, the saved or default width is used.
-.Ss \&SB
+.Pp
+See also
+.Ic RE .
+.It Ic SB
 Text is rendered in small size (one point smaller than the default font)
 bold face.
-.Ss \&SH
-Begin a section.  The scope of a section is only closed by another
-section or the end of file.  The paragraph left-margin width is re-set
-to the default.
-.Ss \&SM
+This macro is an extension that probably first appeared in SunOS 4.0
+and was later adopted by GNU and by
+.Bx 4.4 .
+.It Ic SH
+Begin a section.
+The scope of a section is only closed by another section or the end of
+file.
+The paragraph left-margin width is reset to the default.
+.It Ic SM
 Text is rendered in small size (one point smaller than the default
 font).
-.Ss \&SS
-Begin a sub-section.  The scope of a sub-section is closed by a
-subsequent sub-section, section, or end of file.  The paragraph
-left-margin width is re-set to the default.
-.Ss \&TH
-Sets the title of the manual page with the following syntax:
-.Bd -filled -offset indent
-.Pf \. Sx \&TH
-.Cm title section
-.Op Cm date Op Cm source Op Cm volume
+.It Ic SS
+Begin a sub-section.
+The scope of a sub-section is closed by a subsequent sub-section,
+section, or end of file.
+The paragraph left-margin width is reset to the default.
+.It Ic SY
+Begin a synopsis block with the following syntax:
+.Bd -unfilled -offset indent
+.Pf . Ic SY Ar command
+.Ar arguments
+.Pf . Ic YS
 .Ed
 .Pp
-At least the upper-case document title
-.Cm title
-and numeric manual section
-.Cm section
-arguments must be provided.  The
-.Cm date
-argument should be formatted as described in
-.Sx Dates :
-if it does not conform, the current date is used instead.  The
-.Cm source
-string specifies the organisation providing the utility.  The
-.Cm volume
-string replaces the default rendered volume, which is dictated by the
-manual section.
+This is a non-standard GNU extension
+and very rarely used even in GNU manual pages.
+Formatting is similar to
+.Ic IP .
+.It Ic TH
+Set the name of the manual page for use in the page header
+and footer with the following syntax:
 .Pp
+.D1 Pf . Ic TH Ar name section date Op Ar source Op Ar volume
+.Pp
+Conventionally, the document
+.Ar name
+is given in all caps.
+The
+.Ar section
+is usually a single digit, in a few cases followed by a letter.
+The recommended
+.Ar date
+format is
+.Sy YYYY-MM-DD
+as specified in the ISO-8601 standard;
+if the argument does not conform, it is printed verbatim.
+If the
+.Ar date
+is empty or not specified, the current date is used.
+The optional
+.Ar source
+string specifies the organisation providing the utility.
+When unspecified,
+.Xr mandoc 1
+uses its
+.Fl Ios
+argument.
+The
+.Ar volume
+string replaces the default volume title of the
+.Ar section .
+.Pp
 Examples:
 .Pp
-.D1 \&.TH CVS 5 "1992-02-12" GNU
-.Ss \&TP
+.Dl \&.TH CVS 5 "1992-02-12" GNU
+.It Ic TP
 Begin a paragraph where the head, if exceeding the indentation width, is
-followed by a newline; if not, the body follows on the same line after a
-buffer to the indentation width.  Subsequent output lines are indented.
+followed by a newline; if not, the body follows on the same line after
+advancing to the indentation width.
+Subsequent output lines are indented.
 The syntax is as follows:
-.Bd -filled -offset indent
-.Pf \. Sx \&TP
-.Op Cm width
+.Bd -unfilled -offset indent
+.Pf . Ic TP Op Ar width
+.Ar head No \e" one line
+.Ar body
 .Ed
 .Pp
 The
-.Cm width
-argument must conform to
-.Sx Scaling Widths .
+.Ar width
+argument is a
+.Xr roff 7
+scaling width.
 If specified, it's saved for later paragraph left-margins; if
 unspecified, the saved or default width is used.
+.It Ic TQ
+Like
+.Ic TP ,
+except that no vertical spacing is inserted before the paragraph.
+This is a non-standard GNU extension
+and very rarely used even in GNU manual pages.
+.It Ic UC
+Sets the volume for the footer for compatibility with man pages from
+.Bx
+releases.
+The optional first argument specifies which release it is from.
+This macro is an extension that first appeared in
+.Bx 3 .
+.It Ic UE
+End a uniform resource identifier block started with
+.Ic UR .
+This is a non-standard GNU extension.
+.It Ic UR
+Begin a uniform resource identifier block.
+This is a non-standard GNU extension.
+It has the following syntax:
+.Bd -unfilled -offset indent
+.Pf . Ic UR Ar uri
+link description to be shown
+.Pf . Ic UE
+.Ed
+.It Ic YS
+End a synopsis block started with
+.Ic SY .
+This is a non-standard GNU extension.
+.It Ic in
+Indent relative to the current indentation:
 .Pp
-See also
-.Sx \&HP ,
-.Sx \&IP ,
-.Sx \&LP ,
-.Sx \&P ,
-and
-.Sx \&PP .
-.\" .
-.\" .
-.\" .Ss \&PD
-.\" Has no effect.  Included for compatibility.
-.\" .
-.\" .
-.\" .Ss \&UC
-.\" Has no effect.  Included for compatibility.
-.Ss \&br
-Breaks the current line.  Consecutive invocations have no further effect.
+.D1 Pf . Ic in Op Ar width
 .Pp
-See also
-.Sx \&sp .
-.Ss \&fi
-End literal mode begun by
-.Sx \&nf .
-.Ss \&i
-Italicise arguments.  Synonym for
-.Sx \&I .
+If
+.Ar width
+is signed, the new offset is relative.
+Otherwise, it is absolute.
+This value is reset upon the next paragraph, section, or sub-section.
+.El
+.Sh MACRO SYNTAX
+The
+.Nm
+macros are classified by scope: line scope or block scope.
+Line macros are only scoped to the current line (and, in some
+situations, the subsequent line).
+Block macros are scoped to the current line and subsequent lines until
+closed by another block macro.
+.Ss Line Macros
+Line macros are generally scoped to the current line, with the body
+consisting of zero or more arguments.
+If a macro is scoped to the next line and the line arguments are empty,
+the next line, which must be text, is used instead.
+Thus:
+.Bd -literal -offset indent
+\&.I
+foo
+.Ed
 .Pp
-See also
-.Sx \&B ,
-.Sx \&I ,
-.Sx \&R .
-.Sx \&b ,
-and
-.Sx \&r .
-.Ss \&na
-Don't align to the right margin.
-.Ss \&nf
-Begin literal mode: all subsequent free-form lines have their end of
-line boundaries preserved.  May be ended by
-.Sx \&fi .
-.Ss \&r
-Fonts and styles (bold face, italics) reset to roman (default font).
+is equivalent to
+.Sq .I foo .
+If next-line macros are invoked consecutively, only the last is used.
+If a next-line macro is followed by a non-next-line macro, an error is
+raised.
 .Pp
-See also
-.Sx \&B ,
-.Sx \&I ,
-.Sx \&R ,
-.Sx \&b ,
-and
-.Sx \&i .
-.Ss \&sp
-Insert vertical spaces into output with the following syntax:
-.Bd -filled -offset indent
-.Pf \. Sx \&sp
-.Op Cm height
+The syntax is as follows:
+.Bd -literal -offset indent
+\&.YO \(lBbody...\(rB
+\(lBbody...\(rB
 .Ed
+.Bl -column "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX" -offset indent
+.It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
+.It Ic AT  Ta    <=1       Ta    current   Ta    \&
+.It Ic B   Ta    n         Ta    next-line Ta    \&
+.It Ic BI  Ta    n         Ta    current   Ta    \&
+.It Ic BR  Ta    n         Ta    current   Ta    \&
+.It Ic DT  Ta    0         Ta    current   Ta    \&
+.It Ic EE  Ta    0         Ta    current   Ta    Version 9 At
+.It Ic EX  Ta    0         Ta    current   Ta    Version 9 At
+.It Ic I   Ta    n         Ta    next-line Ta    \&
+.It Ic IB  Ta    n         Ta    current   Ta    \&
+.It Ic IR  Ta    n         Ta    current   Ta    \&
+.It Ic OP  Ta    >=1       Ta    current   Ta    GNU
+.It Ic PD  Ta    1         Ta    current   Ta    \&
+.It Ic RB  Ta    n         Ta    current   Ta    \&
+.It Ic RI  Ta    n         Ta    current   Ta    \&
+.It Ic SB  Ta    n         Ta    next-line Ta    \&
+.It Ic SM  Ta    n         Ta    next-line Ta    \&
+.It Ic TH  Ta    >1, <6    Ta    current   Ta    \&
+.It Ic UC  Ta    <=1       Ta    current   Ta    \&
+.It Ic in  Ta    1         Ta    current   Ta    Xr roff 7
+.El
+.Ss Block Macros
+Block macros comprise a head and body.
+As with in-line macros, the head is scoped to the current line and, in
+one circumstance, the next line (the next-line stipulations as in
+.Sx Line Macros
+apply here as well).
 .Pp
-Insert
-.Cm height
-spaces, which must conform to
-.Sx Scaling Widths .
-If 0, this is equivalent to the
-.Sx \&br
-macro.  Defaults to 1, if unspecified.
+The syntax is as follows:
+.Bd -literal -offset indent
+\&.YO \(lBhead...\(rB
+\(lBhead...\(rB
+\(lBbody...\(rB
+.Ed
 .Pp
-See also
-.Sx \&br .
-.\" .Ss \&Sp
-.\" A synonym for
-.\" .Sx \&sp
-.\" .Cm 0.5v .
-.\" .
-.\" .Ss \&Vb
-.\" A synonym for
-.\" .Sx \&nf .
-.\" Accepts an argument (the height of the formatted space) which is
-.\" disregarded.
-.\" .
-.\" .Ss \&Ve
-.\" A synonym for
-.\" .Sx \&fi .
-.\" .
-.Sh COMPATIBILITY
-This section documents areas of questionable portability between
-implementations of the
-.Nm
-language.
+The closure of body scope may be to the section, where a macro is closed
+by
+.Ic SH ;
+sub-section, closed by a section or
+.Ic SS ;
+or paragraph, closed by a section, sub-section,
+.Ic HP ,
+.Ic IP ,
+.Ic LP ,
+.Ic P ,
+.Ic PP ,
+.Ic RE ,
+.Ic SY ,
+or
+.Ic TP .
+No closure refers to an explicit block closing macro.
 .Pp
-.Bl -dash -compact
-.It
-In quoted literals, GNU troff allowed pair-wise double-quotes to produce
-a standalone double-quote in formatted output.  It is not known whether
-this behaviour is exhibited by other formatters.
-.It
-Blocks of whitespace are stripped from macro and free-form text lines
-(except when in literal mode) in mandoc.  This is not the case for GNU
-troff: for maximum portability, whitespace sensitive blocks should be
-enclosed in literal contexts.
-.It
-The
-.Sx \&sp
-macro does not accept negative values in mandoc.  In GNU troff, this
-would result in strange behaviour.
-.It
-The
-.Sq \(aq
-macro control character, in GNU troff (and prior troffs) suppresses a
-newline before macro output; in mandoc, it is an alias for the standard
-.Sq \&.
-control character.
+As a rule, block macros may not be nested; thus, calling a block macro
+while another block macro scope is open, and the open scope is not
+implicitly closed, is syntactically incorrect.
+.Bl -column "MacroX" "ArgumentsX" "Head ScopeX" "sub-sectionX" "compatX" -offset indent
+.It Em Macro Ta Em Arguments Ta Em Head Scope Ta Em Body Scope  Ta Em Notes
+.It Ic HP  Ta    <2        Ta    current    Ta    paragraph   Ta    \&
+.It Ic IP  Ta    <3        Ta    current    Ta    paragraph   Ta    \&
+.It Ic LP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Ic ME  Ta    0         Ta    none       Ta    none        Ta    GNU
+.It Ic MT  Ta    1         Ta    current    Ta    to \&ME     Ta    GNU
+.It Ic P   Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Ic PP  Ta    0         Ta    current    Ta    paragraph   Ta    \&
+.It Ic RE  Ta    <=1       Ta    current    Ta    none        Ta    \&
+.It Ic RS  Ta    1         Ta    current    Ta    to \&RE     Ta    \&
+.It Ic SH  Ta    >0        Ta    next-line  Ta    section     Ta    \&
+.It Ic SS  Ta    >0        Ta    next-line  Ta    sub-section Ta    \&
+.It Ic SY  Ta    1         Ta    current    Ta    to \&YS     Ta    GNU
+.It Ic TP  Ta    n         Ta    next-line  Ta    paragraph   Ta    \&
+.It Ic TQ  Ta    n         Ta    next-line  Ta    paragraph   Ta    GNU
+.It Ic UE  Ta    0         Ta    current    Ta    none        Ta    GNU
+.It Ic UR  Ta    1         Ta    current    Ta    part        Ta    GNU
+.It Ic YS  Ta    0         Ta    none       Ta    none        Ta    GNU
 .El
+.Pp
+If a block macro is next-line scoped, it may only be followed by in-line
+macros for decorating text.
+.Ss Font handling
+In
+.Nm
+documents, both
+.Sx Physical markup
+macros and
+.Xr roff 7
+.Ql \ef
+font escape sequences can be used to choose fonts.
+In text lines, the effect of manual font selection by escape sequences
+only lasts until the next macro invocation; in macro lines, it only lasts
+until the end of the macro scope.
+Note that macros like
+.Ic BR
+open and close a font scope for each argument.
 .Sh SEE ALSO
+.Xr man 1 ,
 .Xr mandoc 1 ,
-.Xr mandoc_char 7
-.Sh AUTHORS
+.Xr eqn 7 ,
+.Xr mandoc_char 7 ,
+.Xr mdoc 7 ,
+.Xr roff 7 ,
+.Xr tbl 7
+.Sh HISTORY
 The
 .Nm
+language first appeared as a macro package for the roff typesetting
+system in
+.At v7 .
+It was later rewritten by
+.An James Clark
+as a macro package for groff.
+.An Eric S. Raymond Aq Mt esr@thyrsus.com
+and
+.An Werner Lemberg Aq Mt wl@gnu.org
+wrote the extended
+.Nm
+macros for groff in 2007.
+The stand-alone implementation that is part of the
+.Xr mandoc 1
+utility written by Kristaps Dzonsons appeared in
+.Ox 4.6 .
+.Sh AUTHORS
+This
+.Nm
 reference was written by
-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
-.Sh CAVEATS
-Do not use this language.  Use
-.Xr mdoc 7 ,
-instead.
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .