===================================================================
RCS file: /cvs/mandoc/man.7,v
retrieving revision 1.62
retrieving revision 1.88
diff -u -p -r1.62 -r1.88
--- mandoc/man.7	2010/04/13 05:26:49	1.62
+++ mandoc/man.7	2010/09/04 17:22:41	1.88
@@ -1,6 +1,6 @@
-.\"	$Id: man.7,v 1.62 2010/04/13 05:26:49 kristaps Exp $
+.\"	$Id: man.7,v 1.88 2010/09/04 17:22:41 kristaps Exp $
 .\"
-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -14,7 +14,7 @@
 .\" 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: September 4 2010 $
 .Dt MAN 7
 .Os
 .Sh NAME
@@ -25,8 +25,8 @@ The
 .Nm man
 language was historically used to format
 .Ux
-manuals.  This reference document describes its syntax, structure, and
-usage.
+manuals.
+This reference document describes its syntax, structure, and usage.
 .Pp
 .Bf -emphasis
 Do not use
@@ -37,12 +37,13 @@ Use the
 .Xr mdoc 7
 language, instead.
 .Pp
-An
+A
 .Nm
 document follows simple rules:  lines beginning with the control
 character
 .Sq \&.
-are parsed for macros.  Other lines are interpreted within the scope of
+are parsed for macros.
+Other lines are interpreted within the scope of
 prior macros:
 .Bd -literal -offset indent
 \&.SH Macro lines change control state.
@@ -51,7 +52,8 @@ Other lines are interpreted within the current state.
 .Sh INPUT ENCODING
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the
-space character, and the tabs character.  All manuals must have
+space character, and the tab character.
+All manuals must have
 .Ux
 line termination.
 .Pp
@@ -59,12 +61,14 @@ Blank lines are acceptable; where found, the output wi
 vertical space.
 .Ss Comments
 Text following a
-.Sq \e\*" ,
+.Sq \e\*q ,
 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.
+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 Special Characters
 Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character
@@ -75,9 +79,11 @@ 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
+or a single one-character sequence.
+See
 .Xr mandoc_char 7
-for a complete list.  Examples include
+for a complete list.
+Examples include
 .Sq \e(em
 .Pq em-dash
 and
@@ -86,56 +92,39 @@ and
 .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
+escape followed by an indicator: B (bold), I (italic), R (Roman), or P
 (revert to previous mode):
 .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.
+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
+The
 .Sq \ef
-attributes are forgotten when entering or exiting a macro block.
+attribute is 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 .
+Whitespace consists of the space character.
+In free-form lines, whitespace is preserved within a line; unescaped
+trailing spaces are stripped from input (unless in a literal context).
+Blank free-form lines, which may include spaces, are permitted and
+rendered as an empty line.
+.Pp
+In macro lines, whitespace delimits arguments and is discarded.
+If arguments are quoted, whitespace within the quotes is retained.
 .Ss Dates
 The
 .Sx \&TH
 macro is the only
 .Nm
-macro that requires a date.  The form for this date is the ISO-8601
+macro that requires a date.
+The form for this date is the ISO-8601
 standard
 .Cm YYYY-MM-DD .
 .Ss Scaling Widths
@@ -148,8 +137,8 @@ stipulating a two-inch paragraph indentation with the 
 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:
+Negative numbers, while accepted, are truncated to zero.
+The following scaling units are accepted:
 .Pp
 .Bl -tag -width Ds -offset indent -compact
 .It c
@@ -200,46 +189,56 @@ this differs from
 .Xr mdoc 7 ,
 which, if a unit is not provided, will instead interpret the string as
 literal text.
+.Ss Sentence Spacing
+When composing a manual, make sure that 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
+.Po
+.Sq \&) ,
+.Sq \&] ,
+.Sq \&' ,
+.Sq \&"
+.Pc .
 .Sh MANUAL STRUCTURE
 Each
 .Nm
-document must contain contains at least the
+document must contain 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.
+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:
+at least one macro or text node must appear in the document.
+Documents are generally structured as follows:
 .Bd -literal -offset indent
 \&.TH FOO 1 2009-10-10
-\&.
 \&.SH NAME
 \efBfoo\efR \e(en a description goes here
-\&.\e\*q The next is for sections 2 & 3 only.
 \&.\e\*q .SH LIBRARY
-\&.
+\&.\e\*q For sections 2 & 3 only.
+\&.\e\*q Not used in OpenBSD.
 \&.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 For sections 2, 3, & 9 only.
 \&.\e\*q .SH ENVIRONMENT
+\&.\e\*q For sections 1, 6, 7, & 8 only.
 \&.\e\*q .SH FILES
+\&.\e\*q .SH EXIT STATUS
+\&.\e\*q For sections 1, 6 & 8 only.
 \&.\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 For sections 1, 4, 6, 7, & 8 only.
 \&.\e\*q .SH ERRORS
+\&.\e\*q For sections 2, 3, & 9 only.
 \&.\e\*q .SH SEE ALSO
 \&.\e\*q .BR foo ( 1 )
 \&.\e\*q .SH STANDARDS
@@ -248,22 +247,23 @@ The \efBfoo\efR utility processes files...
 \&.\e\*q .SH CAVEATS
 \&.\e\*q .SH BUGS
 \&.\e\*q .SH SECURITY CONSIDERATIONS
+\&.\e\*q Not used in OpenBSD.
 .Ed
 .Pp
 The sections in a
 .Nm
-document are conventionally ordered as they appear above.  Sections
-should be composed as follows:
+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:
+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:
+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
@@ -291,34 +291,32 @@ This expands upon the brief, one-line description in
 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.
+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.
+This section 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.).
+Documents files used.
+It's helpful to document both the file name and a short description of how
+the file is used (created, modified, etc.).
+.It Em EXIT STATUS
+This section documents the command exit status for
+section 1, 6, and 8 utilities.
+Historically, this information was described in
+.Em DIAGNOSTICS ,
+a practise that is now discouraged.
 .It Em EXAMPLES
-Example usages.  This often contains snippets of well-formed,
-well-tested invocations.  Make doubly sure that your examples work
-properly!
+Example usages.
+This often contains snippets of well-formed,
+well-tested invocations.
+Make sure that examples work properly!
 .It Em DIAGNOSTICS
-Documents error conditions.  This is most useful in section 4 manuals.
+Documents error conditions.
+This is most useful in section 4 manuals.
 Historically, this section was used in place of
 .Em EXIT STATUS
 for manuals in sections 1, 6, and 8; however, this practise is
@@ -326,8 +324,8 @@ 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.
+References other manuals with related topics.
+This section should exist for most manuals.
 .Pp
 .D1 \&.BR bar \&( 1 \&),
 .Pp
@@ -342,29 +340,30 @@ 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.
+A brief history of the subject, including where support first appeared.
 .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.
+Credits to the person or persons who wrote the code and/or documentation.
+Authors should generally be noted by both name and email address.
 .It Em CAVEATS
-Explanations of common misuses and misunderstandings should be explained
+Common misuses and misunderstandings should be explained
 in this section.
 .It Em BUGS
-Extant bugs should be described in this section.
+Known bugs, limitations, and work-arounds should be described
+in this section.
 .It Em SECURITY CONSIDERATIONS
 Documents any security precautions that operators should consider.
 .El
 .Sh MACRO SYNTAX
-Macros are one to three three characters in length and begin with a
-control character ,
+Macros are one to three characters in length and begin with a
+control character,
 .Sq \&. ,
-at the beginning of the line.  The
+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:
+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
@@ -372,15 +371,17 @@ the macro name.  Thus, the following are equivalent:
 .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.
+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:
+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
@@ -390,11 +391,11 @@ 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
+raised, except for
 .Sx \&br ,
 .Sx \&sp ,
-or
-.Sx \&na ) .
+and
+.Sx \&na .
 .Pp
 The syntax is as follows:
 .Bd -literal -offset indent
@@ -404,6 +405,7 @@ The syntax is as follows:
 .Pp
 .Bl -column -compact -offset indent "MacroX" "ArgumentsX" "ScopeXXXXX" "CompatX"
 .It Em Macro Ta Em Arguments Ta Em Scope     Ta Em Notes
+.It Sx \&AT  Ta    <=1       Ta    current   Ta    \&
 .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    \&
@@ -418,15 +420,16 @@ The syntax is as follows:
 .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 \&UC  Ta    <=1       Ta    current   Ta    \&
 .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 \&in  Ta    1         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 \&Sp  Ta    <1        Ta    current   Ta    compat
 .\" .It Sx \&Vb  Ta    <1        Ta    current   Ta    compat
 .\" .It Sx \&Ve  Ta    0         Ta    current   Ta    compat
 .El
@@ -434,14 +437,14 @@ The syntax is as follows:
 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
+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
+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
@@ -496,8 +499,14 @@ If a block macro is next-line scoped, it may only be f
 macros for decorating text.
 .Sh 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 \&AT
+Sets the volume for the footer for compatibility with man pages from
+.Tn AT&T UNIX
+releases.
+The optional arguments specify which release it is from.
 .Ss \&B
 Text is rendered in bold face.
 .Pp
@@ -509,7 +518,8 @@ See also
 and
 .Sx \&r .
 .Ss \&BI
-Text is rendered alternately in bold face and italic.  Thus,
+Text is rendered alternately in bold face and italic.
+Thus,
 .Sq .BI this word and that
 causes
 .Sq this
@@ -519,7 +529,8 @@ 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:
 .Pp
@@ -554,7 +565,8 @@ See also
 and
 .Sx \&IR .
 .Ss \&DT
-Has no effect.  Included for compatibility.
+Has no effect.
+Included for compatibility.
 .Ss \&HP
 Begin a paragraph whose initial output line is left-justified, but
 subsequent output lines are indented, with the following syntax:
@@ -588,8 +600,8 @@ See also
 and
 .Sx \&r .
 .Ss \&IB
-Text is rendered alternately in italics and bold face.  Whitespace
-between arguments is omitted in output.
+Text is rendered alternately in italics and bold face.
+Whitespace between arguments is omitted in output.
 .Pp
 See
 .Sx \&BI
@@ -612,14 +624,14 @@ Begin an indented paragraph with the following syntax:
 The
 .Cm width
 argument defines the width of the left margin and is defined by
-.Sx Scaling Widths ,
+.Sx Scaling Widths .
 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.
+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 ,
@@ -644,9 +656,10 @@ See also
 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.
+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.
 .Pp
 See also
 .Sx \&HP ,
@@ -721,9 +734,9 @@ See also
 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
+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 .
 This has the following syntax:
 .Bd -filled -offset indent
@@ -740,16 +753,18 @@ If not specified, the saved or default width is used.
 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.
+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.
 .Ss \&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.
+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.
 .Ss \&TH
 Sets the title of the manual page with the following syntax:
 .Bd -filled -offset indent
@@ -758,17 +773,21 @@ Sets the title of the manual page with the following s
 .Op Cm date Op Cm source Op Cm volume
 .Ed
 .Pp
-At least the upper-case document title
+At least the upper-case document
 .Cm title
-and numeric manual section
+and the manual
 .Cm section
-arguments must be provided.  The
+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
+.Sx Dates ,
+but will be printed verbatim if it is not.
+If the date is not specified, the current date is used.
+The
 .Cm source
-string specifies the organisation providing the utility.  The
+string specifies the organisation providing the utility.
+The
 .Cm volume
 string replaces the default rendered volume, which is dictated by the
 manual section.
@@ -779,7 +798,8 @@ Examples:
 .Ss \&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.
+buffer to the indentation width.
+Subsequent output lines are indented.
 The syntax is as follows:
 .Bd -filled -offset indent
 .Pf \. Sx \&TP
@@ -806,10 +826,13 @@ and
 .\" Has no effect.  Included for compatibility.
 .\" .
 .\" .
-.\" .Ss \&UC
-.\" Has no effect.  Included for compatibility.
+.Ss \&UC
+Sets the volume for the footer for compatibility with man pages from
+BSD releases.
+The optional first argument specifies which release it is from.
 .Ss \&br
-Breaks the current line.  Consecutive invocations have no further effect.
+Breaks the current line.
+Consecutive invocations have no further effect.
 .Pp
 See also
 .Sx \&sp .
@@ -817,7 +840,8 @@ See also
 End literal mode begun by
 .Sx \&nf .
 .Ss \&i
-Italicise arguments.  Synonym for
+Italicise arguments.
+Synonym for
 .Sx \&I .
 .Pp
 See also
@@ -827,11 +851,22 @@ See also
 .Sx \&b ,
 and
 .Sx \&r .
+.Ss \&in
+Indent relative to the current indentation:
+.Pp
+.D1 Pf \. Sx \&in Op Cm width
+.Pp
+If
+.Cm width
+is signed, the new offset is relative.
+Otherwise, it is absolute.
+This value is reset upon the next paragraph, section, or sub-section.
 .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
+line boundaries preserved.
+May be ended by
 .Sx \&fi .
 .Ss \&r
 Fonts and styles (bold face, italics) reset to roman (default font).
@@ -856,7 +891,8 @@ spaces, which must conform to
 .Sx Scaling Widths .
 If 0, this is equivalent to the
 .Sx \&br
-macro.  Defaults to 1, if unspecified.
+macro.
+Defaults to 1, if unspecified.
 .Pp
 See also
 .Sx \&br .
@@ -884,35 +920,67 @@ language.
 .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.
+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.
+troff suppresses a newline before
+.Sq \(aq
+macro output; in mandoc, it is an alias for the standard
+.Sq \&.
+control character.
 .It
 The
-.Sx \&sp
-macro does not accept negative values in mandoc.  In GNU troff, this
-would result in strange behaviour.
+.Sq \eh
+.Pq horizontal position ,
+.Sq \ev
+.Pq vertical position ,
+.Sq \em
+.Pq text colour ,
+.Sq \eM
+.Pq text filling colour ,
+.Sq \ez
+.Pq zero-length character ,
+.Sq \ew
+.Pq string length ,
+.Sq \ek
+.Pq horizontal position marker ,
+.Sq \eo
+.Pq text overstrike ,
+and
+.Sq \es
+.Pq text size
+escape sequences are all discarded in mandoc.
 .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.
+.Sq \ef
+scaling unit is accepted by mandoc, but rendered as the default unit.
+.It
+The
+.Sx \&sp
+macro does not accept negative values in mandoc.
+In GNU troff, this would result in strange behaviour.
 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr mandoc_char 7
-.Sh AUTHORS
+.Sh HISTORY
 The
 .Nm
+language first appeared as a macro package for the roff typesetting
+system in
+.At v7 .
+It was later rewritten by James Clark as a macro package for groff.
+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
+Do not use this language.
+Use
 .Xr mdoc 7 ,
 instead.