Reorganize part of the content:

1) Move the LANGUAGE SYNTAX from mdoc(7) and man(7) to roff(7),
it's common to both and it's actually roff syntax.
2) Move the MACRO SYNTAX down to the bottom, such that the less
technical parts MANUAL STRUCTURE and MACRO OVERVIEW get to the top.

Getting everything to again fit together after the reshuffling
required various adjustments; also adjust and improve
the DESCRIPTIONS while there.

feedback and "go ahead"  jmc@ kristaps@

1 files changed, 177 insertions, 396 deletions

diff --git a/man.7 b/man.7
index 3d5f6642..fa7dbb0a 100644
--- a/man.7
+++ b/man.7
@@ -1,6 +1,7 @@
 .\"	$Id$
 .\"
-.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -19,276 +20,63 @@
 .Os
 .Sh NAME
 .Nm man
-.Nd man language reference
+.Nd legacy formatting language for manual pages
 .Sh DESCRIPTION
-The
+Traditionally, the
 .Nm man
-language was historically used to format
+language has been used to write
 .Ux
-manuals.
-This reference document describes its syntax, structure, and usage.
+manuals for the
+.Xr man 1
+utility.
+It supports limited control of presentational details like fonts,
+indentation and spacing.
+This reference document describes the structure of manual pages
+and the syntax and usage of the man language.
 .Pp
 .Bf -emphasis
 Do not use
 .Nm
-to write your manuals.
+to write your manuals:
 .Ef
+It lacks support for semantic markup.
 Use the
 .Xr mdoc 7
 language, instead.
 .Pp
-A
+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.
-Lines not beginning with the control character 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 available 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.
 Text lines are interpreted within the current state.
 .Ed
-.Sh LANGUAGE SYNTAX
-.Nm
-documents may contain only graphable 7-bit ASCII characters, the
-space character, and the tab character.
-The back-space character
-.Sq \e
-indicates the start of an escape sequence for
-.Sx Comments ,
-.Sx Predefined Strings ,
-and
-.Sx Special Characters .
-.Ss Comments
-Text following an escaped double-quote
-.Sq \e\(dq ,
-whether in a macro or text line, is ignored to the end of
-line.
-A macro line beginning with a control character and comment escape
-.Sq \&.\e\(dq
-is also ignored.
-Furthermore,
-macro lines with only a control character and optional trailing
-whitespace are
-stripped from input.
-.Pp
-Examples:
-.Bd -literal -offset indent -compact
-\&.\e\(dq This is a comment line.
-\&.\e\(dq The next line is ignored:
-\&.
-\&.Em Emphasis \e\(dq This is also a comment.
-.Ed
-.Ss Special Characters
-Special characters are used to encode special glyphs and are rendered
-differently across output media.
-They may occur in both macro and text 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.
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It Li \e(em
-Two-letter em dash escape.
-.It Li \ee
-One-letter backslash escape.
-.El
-.Pp
-See
-.Xr mandoc_char 7
-for a complete list.
-.Ss Text Decoration
-Terms may be text-decorated using the
-.Sq \ef
-escape followed by an indicator: B (bold), I (italic), R (regular), or P
-(revert to previous mode).
-A numerical representation 3, 2, or 1 (bold, italic, and regular,
-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
-The
-.Sq \ef
-attribute is forgotten when entering or exiting a macro block.
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It Li \efBbold\efR
-Write in bold, then switch to regular font mode.
-.It Li \efIitalic\efP
-Write in italic, then return to previous font mode.
-.El
-.Ss Predefined Strings
-Predefined strings, like
-.Sx Special Characters ,
-mark special output glyphs.
-Predefined strings are escaped with the slash-asterisk,
-.Sq \e* :
-single-character
-.Sq \e*X ,
-two-character
-.Sq \e*(XX ,
-and N-character
-.Sq \e*[N] .
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It Li \e*(Am
-Two-letter ampersand predefined string.
-.It Li \e*q
-One-letter double-quote predefined string.
-.El
 .Pp
-These strings are set using
-.Xr roff 7 ,
-although
+Many aspects of the basic syntax of the
 .Nm
-consists of several pre-set escapes listed in
-.Xr mandoc_char 7 .
-.Ss Whitespace
-Whitespace consists of the space character.
-In text lines, whitespace is preserved within a line.
-In macro lines, whitespace delimits arguments and is discarded.
-.Pp
-Unescaped trailing spaces are stripped from text line input unless in a
-literal context.
-In general, trailing whitespace on any input line is discouraged for
-reasons of portability.
-In the rare case that a blank character is needed at the end of an
-input line, it may be forced by
-.Sq \e\ \e& .
-.Pp
-In general, space characters can be rendered as literal
-characters by using non-breaking space escapes or
-.Sx Quotation .
-If the first character of a text line is a space, that line is printed
-with a leading newline.
-.Ss Quotation
-Macro arguments may be quoted with double-quotes to so that the
-enclosed text is one literal term.
-Quoted text, even if whitespace or if it would cause a macro invocation
-when unquoted, is considered literal text.
-.Pp
-A quoted argument begins with a double-quote preceded by whitespace.
-The next double-quote not pairwise adjacent to another double-quote
-terminates the literal, regardless of surrounding whitespace.
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It Li .BR a \(dqb c\(dq d
-Group arguments
-.Qq b c
-into one un-bolded argument.
-If unspecified,
-.Qq a
-and
-.Qq c
-will be in bold,
-.Qq b
-and
-.Qq d
-in regular font mode.
-Furthermore, will be preserved between
-.Qq b
+language are based on the
+.Xr roff 7
+language; see the
+.Em LANGUAGE SYNTAX
 and
-.Qq c .
-.El
-.Ss Scaling Widths
-Many macros support scaled widths for their arguments.
-The syntax for a scaled width 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.
-.Pp
-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.
-See
-.Sx COMPATIBILITY .
-.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.
-.Pp
-Examples:
-.Bl -tag -width Ds -offset indent -compact
-.It \&.HP 2i
-two-inch tagged list indentation
-.Pq see Sx \&HP
-.It \&.sp 2v
-two vertical spaces
-.Pq see Sx \&sp
-.El
-.Ss Sentence Spacing
-Sentences should terminate at the end of an input line.
-By doing this, a formatter 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 .
-.Pp
-Examples:
-.Bd -literal -offset indent -compact
-Do not end sentences mid-line like this.  Instead,
-end a sentence like this.
-A new sentence gets a new line.
-.Ed
+.Em MACRO SYNTAX
+sections in the
+.Xr roff 7
+manual for details, in particular regarding
+comments, escape sequences, whitespace, and quoting.
 .Sh MANUAL STRUCTURE
 Each
 .Nm
@@ -300,7 +88,7 @@ appears as the first macro.
 .Pp
 Beyond
 .Sx \&TH ,
-at least one macro or text node must appear in the document.
+at least one macro or text line must appear in the document.
 .Pp
 The following is a well-formed skeleton
 .Nm
@@ -445,150 +233,6 @@ in this section.
 .It Em SECURITY CONSIDERATIONS
 Documents any security precautions that operators should consider.
 .El
-.Sh MACRO SYNTAX
-Macros are one to 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
-To include space characters in macro arguments, arguments may be quoted;
-see the
-.Sq MACRO SYNTAX
-section in the
-.Xr roff 7
-manual for details.
-.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, except for
-.Sx \&br ,
-.Sx \&sp ,
-and
-.Sx \&na .
-.Pp
-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 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    \&
-.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 \&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    <=1       Ta    current   Ta    \&
-.It Sx \&br  Ta    0         Ta    current   Ta    compat
-.It Sx \&fi  Ta    0         Ta    current   Ta    compat
-.It Sx \&ft  Ta    1         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 \&sp  Ta    1         Ta    current   Ta    compat
-.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 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
-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.
-.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 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    \&
-.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 MACRO OVERVIEW
 This overview is sorted such that macros of similar purpose are listed
 together, to help find the best macro for any given purpose.
@@ -628,7 +272,7 @@ in the alphabetical reference below.
 .It Sx RB Ta alternate between roman and boldface fonts
 .It Sx RI Ta alternate between roman and italic fonts
 .El
-.Sh REFERENCE
+.Sh MACRO REFERENCE
 This section is a canonical reference to all macros, arranged
 alphabetically.
 For the scoping of individual macros, see
@@ -1003,6 +647,143 @@ Defaults to 1, if unspecified.
 .Pp
 See also
 .Sx \&br .
+.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
+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, except for
+.Sx \&br ,
+.Sx \&sp ,
+and
+.Sx \&na .
+.Pp
+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 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    \&
+.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 \&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    <=1       Ta    current   Ta    \&
+.It Sx \&br  Ta    0         Ta    current   Ta    compat
+.It Sx \&fi  Ta    0         Ta    current   Ta    compat
+.It Sx \&ft  Ta    1         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 \&sp  Ta    1         Ta    current   Ta    compat
+.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 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
+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.
+.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 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    \&
+.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.
+.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
+.Sx \&BR
+open and close a font scope for each argument.
 .Sh COMPATIBILITY
 This section documents areas of questionable portability between
 implementations of the