Stripping out of `\w' groff escape. Yet another for pod2man...

[mandoc.git] / mdoc.7

diff --git a/mdoc.7 b/mdoc.7
index 570ef61f053fb099a5c464872532e3dcf0e285a4..39c771b7e98f5ef124687aa3b643f79e7d7a2e84 100644 (file)
--- a/mdoc.7
+++ b/mdoc.7
@@ -1,4 +1,4 @@
-.\"    $Id: mdoc.7,v 1.137 2010/07/19 10:48:36 kristaps Exp $
+.\"    $Id: mdoc.7,v 1.153 2010/08/24 13:07:01 kristaps Exp $

 .\"
 .\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>


@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"

-.Dd $Mdocdate: July 19 2010 $
+.Dd $Mdocdate: August 24 2010 $

 .Dt MDOC 7
 .Os
 .Sh NAME
 .Dt MDOC 7
 .Os
 .Sh NAME


@@ -27,8 +27,12 @@ The
 language is used to format
 .Bx
 .Ux
 language is used to format
 .Bx
 .Ux

-manuals.  In this reference document, we describe its syntax, structure,
-and usage.  Our reference implementation is mandoc; the
+manuals.
+This reference document describes its syntax, structure, and
+usage.
+The reference implementation is
+.Xr mandoc 1 ;
+the

 .Sx COMPATIBILITY
 section describes compatibility with other troff \-mdoc implementations.
 .Pp
 .Sx COMPATIBILITY
 section describes compatibility with other troff \-mdoc implementations.
 .Pp


@@ -37,7 +41,8 @@ An
 document follows simple rules: lines beginning with the control
 character
 .Sq \.
 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.
 prior macros:
 .Bd -literal -offset indent
 \&.Sh Macro lines change control state.


@@ -46,18 +51,20 @@ Other lines are interpreted within the current state.
 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space
 .Sh LANGUAGE SYNTAX
 .Nm
 documents may contain only graphable 7-bit ASCII characters, the space

-character, and, in certain circumstances, the tab character.  All
-manuals must have
+character, and, in certain circumstances, the tab character.
+All manuals must have

 .Ux
 line terminators.
 .Ss Comments
 Text following a
 .Sq \e\*q ,
 whether in a macro or free-form text line, is ignored to the end of
 .Ux
 line terminators.
 .Ss Comments
 Text following a
 .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,
+line.
+A macro line with only a control character and comment escape,

 .Sq \&.\e\*q ,
 .Sq \&.\e\*q ,

-is also ignored.  Macro lines with only a control character and optionally
-whitespace are stripped from input.
+is also ignored.
+Macro lines with only a control character and optional whitespace are
+stripped from input.

 .Ss Reserved Characters
 Within a macro line, the following characters are reserved:
 .Pp
 .Ss Reserved Characters
 Within a macro line, the following characters are reserved:
 .Pp


@@ -88,10 +95,10 @@ Within a macro line, the following characters are reserved:
 .Pp
 Use of reserved characters is described in
 .Sx MACRO SYNTAX .
 .Pp
 Use of reserved characters is described in
 .Sx MACRO SYNTAX .

-For general use in macro lines, these characters must either be escaped
+For general use in macro lines, these characters can either be escaped

 with a non-breaking space
 .Pq Sq \e&
 with a non-breaking space
 .Pq Sq \e&

-or, if applicable, an appropriate escape sequence used.
+or, if applicable, an appropriate escape sequence can be used.

 .Ss Special Characters
 Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character
 .Ss Special Characters
 Special characters may occur in both macro and free-form lines.
 Sequences begin with the escape character


@@ -102,7 +109,7 @@ for two-character sequences; an open-bracket
 .Sq \&[
 for n-character sequences (terminated at a close-bracket
 .Sq \&] ) ;
 .Sq \&[
 for n-character sequences (terminated at a close-bracket
 .Sq \&] ) ;

-or a single one-character sequence.
+or a single one character sequence.

 See
 .Xr mandoc_char 7
 for a complete list.
 See
 .Xr mandoc_char 7
 for a complete list.


@@ -115,7 +122,7 @@ and
 .Ss Text Decoration
 Terms may be text-decorated using the
 .Sq \ef
 .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
 (revert to previous mode):
 .Pp
 .D1 \efBbold\efR \efIitalic\efP


@@ -142,7 +149,7 @@ recommended for
 which encourages semantic annotation.
 .Ss Predefined Strings
 Historically,
 which encourages semantic annotation.
 .Ss Predefined Strings
 Historically,

-.Xr groff 1
+troff

 also defined a set of package-specific
 .Dq predefined strings ,
 which, like
 also defined a set of package-specific
 .Dq predefined strings ,
 which, like


@@ -167,7 +174,7 @@ and
 .Pq vertical bar .
 .Ss Whitespace
 Whitespace consists of the space character.
 .Pq vertical bar .
 .Ss Whitespace
 Whitespace consists of the space character.

-In free-form lines, whitespace is preserved within a line; un-escaped
+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 whitespace, are only permitted
 within literal contexts.
 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.


@@ -175,24 +182,18 @@ within literal contexts.
 In macro lines, whitespace delimits arguments and is discarded.
 If arguments are quoted, whitespace within the quotes is retained.
 .Ss Quotation
 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
+Macro arguments may be quoted with double-quotes to group

 space-delimited terms or to retain blocks of whitespace.
 A quoted argument begins with a double-quote preceded by whitespace.
 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
+The next double-quote not pairwise adjacent to another double-quote

 terminates the literal, regardless of surrounding whitespace.
 .Pp
 terminates the literal, regardless of surrounding whitespace.
 .Pp

-This produces tokens
-.Sq a" ,
-.Sq b c ,
-.Sq de ,
-and
-.Sq fg" .
-Note that any quoted term, be it argument or macro, is indiscriminately
-considered literal text.
+Note that any quoted text, even if it would cause a macro invocation
+when unquoted, is considered literal text.

 Thus, the following produces
 Thus, the following produces

-.Sq \&Em a :
+.Sq Op "Fl a" :

 .Bd -literal -offset indent
 .Bd -literal -offset indent

-\&.Em "Em a"
+\&.Op "Fl a"

 .Ed
 .Pp
 In free-form mode, quotes are regarded as opaque text.
 .Ed
 .Pp
 In free-form mode, quotes are regarded as opaque text.


@@ -277,7 +278,7 @@ is necessarily non-portable across output media.
 See
 .Sx COMPATIBILITY .
 .Ss Sentence Spacing
 See
 .Sx COMPATIBILITY .
 .Ss Sentence Spacing

-When composing a manual, make sure that your sentences end at the end of
+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,
 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,


@@ -289,7 +290,8 @@ delimiters (
 .Sq \&" ) .
 .Pp
 The proper spacing is also intelligently preserved if a sentence ends at
 .Sq \&" ) .
 .Pp
 The proper spacing is also intelligently preserved if a sentence ends at

-the boundary of a macro line, e.g.,
+the boundary of a macro line.
+For example:

 .Pp
 .D1 \&Xr mandoc 1 \.
 .D1 \&Fl T \&Ns \&Cm ascii \.
 .Pp
 .D1 \&Xr mandoc 1 \.
 .D1 \&Fl T \&Ns \&Cm ascii \.


@@ -299,12 +301,12 @@ A well-formed
 document consists of a document prologue followed by one or more
 sections.
 .Pp
 document consists of a document prologue followed by one or more
 sections.
 .Pp

-The prologue, which consists of (in order) the
+The prologue, which consists of the

 .Sx \&Dd ,
 .Sx \&Dt ,
 and
 .Sx \&Os
 .Sx \&Dd ,
 .Sx \&Dt ,
 and
 .Sx \&Os

-macros, is required for every document.
+macros in that order, is required for every document.

 .Pp
 The first section (sections are denoted by
 .Sx \&Sh )
 .Pp
 The first section (sections are denoted by
 .Sx \&Sh )


@@ -362,19 +364,19 @@ utility processes files ...
 \&.\e\*q .Sh SECURITY CONSIDERATIONS
 .Ed
 .Pp
 \&.\e\*q .Sh SECURITY CONSIDERATIONS
 .Ed
 .Pp

-The sections in a
+The sections in an

 .Nm
 document are conventionally ordered as they appear above.
 Sections should be composed as follows:
 .Bl -ohang -offset Ds
 .It Em NAME
 .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 name(s) and a one line description of the documented material.

 The syntax for this as follows:
 .Bd -literal -offset indent
 The syntax for this as follows:
 .Bd -literal -offset indent

-\&.Nm name0
-\&.Nm name1
+\&.Nm name0 ,
+\&.Nm name1 ,

 \&.Nm name2
 \&.Nm name2

-\&.Nd a short description
+\&.Nd a one line description

 .Ed
 .Pp
 The
 .Ed
 .Pp
 The


@@ -416,8 +418,8 @@ generally structured as follows:
 .Pp
 For the second, function calls (sections 2, 3, 9):
 .Bd -literal -offset indent
 .Pp
 For the second, function calls (sections 2, 3, 9):
 .Bd -literal -offset indent

-\&.Vt extern const char *global;

 \&.In header.h
 \&.In header.h

+\&.Vt extern const char *global;

 \&.Ft "char *"
 \&.Fn foo "const char *src"
 \&.Ft "char *"
 \&.Ft "char *"
 \&.Fn foo "const char *src"
 \&.Ft "char *"


@@ -445,8 +447,8 @@ section, particularly
 .Sx \&Vt ,
 and
 .Sx \&Ft .
 .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
+All of these macros are output on their own line.
+If two such dissimilar macros are pairwise invoked (except for

 .Sx \&Ft
 before
 .Sx \&Fo
 .Sx \&Ft
 before
 .Sx \&Fo


@@ -467,14 +469,14 @@ with the text immediately following the
 .Sx \&Nm
 macro, up to the next
 .Sx \&Nm ,
 .Sx \&Nm
 macro, up to the next
 .Sx \&Nm ,

-.Sx \&Sx ,
+.Sx \&Sh ,

 or
 .Sx \&Ss
 macro or the end of an enclosing block, whichever comes first.
 .It Em DESCRIPTION
 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
+This expands upon the brief, one line description in

 .Em NAME .
 .Em NAME .

-It usually contains a break-down of the options (if documenting a
+It usually contains a breakdown of the options (if documenting a

 command), such as:
 .Bd -literal -offset indent
 The arguments are as follows:
 command), such as:
 .Bd -literal -offset indent
 The arguments are as follows:


@@ -490,31 +492,30 @@ 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 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.

 .Pp
 See
 .Sx \&Rv .
 .It Em ENVIRONMENT
 .Pp
 See
 .Sx \&Rv .
 .It Em ENVIRONMENT

-Documents any usages of environment variables, e.g.,
-.Xr environ 7 .
+Lists the environment variables used by the utility,
+and explains the syntax and semantics of their values.
+The
+.Xr environ 7
+manual provides examples of typical content and formatting.

 .Pp
 See
 .Sx \&Ev .
 .It Em FILES
 Documents files used.
 .Pp
 See
 .Sx \&Ev .
 .It Em FILES
 Documents files used.

-It's helpful to document both the file and a short description of how
+It's helpful to document both the file name and a short description of how

 the file is used (created, modified, etc.).
 .Pp
 See
 .Sx \&Pa .
 .It Em EXIT STATUS
 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.
+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.
 Historically, this information was described in
 .Em DIAGNOSTICS ,
 a practise that is now discouraged.


@@ -524,7 +525,7 @@ See
 .It Em EXAMPLES
 Example usages.
 This often contains snippets of well-formed, well-tested invocations.
 .It Em EXAMPLES
 Example usages.
 This often contains snippets of well-formed, well-tested invocations.

-Make doubly sure that your examples work properly!
+Make sure that examples work properly!

 .It Em DIAGNOSTICS
 Documents error conditions.
 This is most useful in section 4 manuals.
 .It Em DIAGNOSTICS
 Documents error conditions.
 This is most useful in section 4 manuals.


@@ -558,26 +559,25 @@ section should be used instead.
 See
 .Sx \&St .
 .It Em HISTORY
 See
 .Sx \&St .
 .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
 .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.

 .Pp
 See
 .Sx \&An .
 .It Em CAVEATS
 .Pp
 See
 .Sx \&An .
 .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
 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
 .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 ,
+control character,

 .Sq \&. ,
 at the beginning of the line.
 An arbitrary amount of whitespace may sit between the control character
 .Sq \&. ,
 at the beginning of the line.
 An arbitrary amount of whitespace may sit between the control character


@@ -610,10 +610,10 @@ produces
 .Sq Fl \&Sh .
 .Pp
 The
 .Sq Fl \&Sh .
 .Pp
 The

-.Em Parsable
+.Em Parsed

 column indicates whether the macro may be followed by further
 (ostensibly callable) macros.
 column indicates whether the macro may be followed by further
 (ostensibly callable) macros.

-If a macro is not parsable, subsequent macro invocations on the line
+If a macro is not parsed, subsequent macro invocations on the line

 will be interpreted as opaque text.
 .Pp
 The
 will be interpreted as opaque text.
 .Pp
 The


@@ -630,8 +630,8 @@ contains a head.
 \&.Yc
 .Ed
 .Pp
 \&.Yc
 .Ed
 .Pp

-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope

 .It Sx \&Bd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ed
 .It Sx \&Bf  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ef
 .It Sx \&Bk  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ek
 .It Sx \&Bd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ed
 .It Sx \&Bf  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ef
 .It Sx \&Bk  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Ek


@@ -653,7 +653,9 @@ All macros have bodies; some
 .Pc
 don't have heads; only one
 .Po
 .Pc
 don't have heads; only one
 .Po

-.Sx \&It Fl column
+.Sx \&It
+in
+.Sx \&Bl Fl column

 .Pc
 has multiple heads.
 .Bd -literal -offset indent
 .Pc
 has multiple heads.
 .Bd -literal -offset indent


@@ -661,8 +663,8 @@ has multiple heads.
 \(lBbody...\(rB
 .Ed
 .Pp
 \(lBbody...\(rB
 .Ed
 .Pp

-.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsableX" "closed by XXXXXXXXXXX"
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Scope
+.Bl -column -compact -offset indent "MacroX" "CallableX" "ParsedX" "closed by XXXXXXXXXXX"
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope

 .It Sx \&It  Ta    \&No     Ta    Yes      Ta    closed by Sx \&It , Sx \&El
 .It Sx \&Nd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh
 .It Sx \&Nm  Ta    \&No     Ta  Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss
 .It Sx \&It  Ta    \&No     Ta    Yes      Ta    closed by Sx \&It , Sx \&El
 .It Sx \&Nd  Ta    \&No     Ta    \&No     Ta    closed by Sx \&Sh
 .It Sx \&Nm  Ta    \&No     Ta  Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss


@@ -697,8 +699,8 @@ and/or tail
 \(lBbody...\(rB \&Yc \(lBtail...\(rB
 .Ed
 .Pp
 \(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
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope

 .It Sx \&Ac  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Ao
 .It Sx \&Ao  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Ac
 .It Sx \&Bc  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Bo
 .It Sx \&Ac  Ta    Yes      Ta    Yes      Ta    opened by Sx \&Ao
 .It Sx \&Ao  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Ac
 .It Sx \&Bc  Ta    Yes      Ta    Yes      Ta    closed by Sx \&Bo


@@ -732,8 +734,8 @@ or end of line.
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
 .Ed
 .Pp
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
 .Ed
 .Pp

-.Bl -column "MacroX" "CallableX" "ParsableX" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable
+.Bl -column "MacroX" "CallableX" "ParsedX" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed

 .It Sx \&Aq  Ta    Yes      Ta    Yes
 .It Sx \&Bq  Ta    Yes      Ta    Yes
 .It Sx \&Brq Ta    Yes      Ta    Yes
 .It Sx \&Aq  Ta    Yes      Ta    Yes
 .It Sx \&Bq  Ta    Yes      Ta    Yes
 .It Sx \&Brq Ta    Yes      Ta    Yes


@@ -766,15 +768,15 @@ If a number (or inequality) of arguments is
 .Pq n ,
 then the macro accepts an arbitrary number of arguments.
 .Bd -literal -offset indent
 .Pq n ,
 then the macro accepts an arbitrary number of arguments.
 .Bd -literal -offset indent

-\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lbres...\(rb
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lBres...\(rB

 
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
 
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
 .Ed
 .Pp
 
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
 
 \&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
 .Ed
 .Pp

-.Bl -column "MacroX" "CallableX" "ParsableX" "Arguments" -compact -offset indent
-.It Em Macro Ta Em Callable Ta Em Parsable Ta Em Arguments
+.Bl -column "MacroX" "CallableX" "ParsedX" "Arguments" -compact -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed 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 \&%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


@@ -800,7 +802,7 @@ then the macro accepts an arbitrary number of arguments.
 .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 \&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 \&Dd  Ta    \&No     Ta    \&No     Ta    n

 .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 \&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


@@ -858,28 +860,27 @@ For the scoping of individual macros, see
 .Ss \&%A
 Author name of an
 .Sx \&Rs
 .Ss \&%A
 Author name of an
 .Sx \&Rs

-block.  Multiple authors should each be accorded their own
+block.
+Multiple authors should each be accorded their own

 .Sx \%%A
 .Sx \%%A

-line.  Author names should be ordered with full or abbreviated
-forename(s) first, then full surname.
+line.
+Author names should be ordered with full or abbreviated forename(s)
+first, then full surname.

 .Ss \&%B
 Book title of an
 .Sx \&Rs
 .Ss \&%B
 Book title of an
 .Sx \&Rs

-block.  This macro may also be used in a non-bibliographic context when
+block.
+This macro may also be used in a non-bibliographic context when

 referring to book titles.
 .Ss \&%C
 Publication city or location of an
 .Sx \&Rs
 block.
 referring to book titles.
 .Ss \&%C
 Publication city or location of an
 .Sx \&Rs
 block.

-.Pp
-.Em Remarks :
-this macro is not implemented in
-.Xr groff 1 .

 .Ss \&%D
 Publication date of an
 .Sx \&Rs
 .Ss \&%D
 Publication date of an
 .Sx \&Rs

-block.  This should follow the reduced or canonical form syntax
-described in
+block.
+This should follow the reduced or canonical form syntax described in

 .Sx Dates .
 .Ss \&%I
 Publisher or issuer name of an
 .Sx Dates .
 .Ss \&%I
 Publisher or issuer name of an


@@ -904,7 +905,8 @@ block.
 .Ss \&%Q
 Institutional author (school, government, etc.) of an
 .Sx \&Rs
 .Ss \&%Q
 Institutional author (school, government, etc.) of an
 .Sx \&Rs

-block.  Multiple institutional authors should each be accorded their own
+block.
+Multiple institutional authors should each be accorded their own

 .Sx \&%Q
 line.
 .Ss \&%R
 .Sx \&%Q
 line.
 .Ss \&%R


@@ -914,8 +916,9 @@ block.
 .Ss \&%T
 Article title of an
 .Sx \&Rs
 .Ss \&%T
 Article title of an
 .Sx \&Rs

-block.  This macro may also be used in a non-bibliographical context
-when referring to article titles.
+block.
+This macro may also be used in a non-bibliographical context when
+referring to article titles.

 .Ss \&%U
 URI of reference document.
 .Ss \&%V
 .Ss \&%U
 URI of reference document.
 .Ss \&%V


@@ -923,51 +926,50 @@ Volume number of an
 .Sx \&Rs
 block.
 .Ss \&Ac
 .Sx \&Rs
 block.
 .Ss \&Ac

-Closes an
+Close an

 .Sx \&Ao
 .Sx \&Ao

-block.  Does not have any tail arguments.
+block.
+Does not have any tail arguments.

 .Ss \&Ad
 .Ss \&Ad

-Address construct: usually in the context of an computational address in
-memory, not a physical (post) address.
+Memory address.
+Do not use this for postal addresses.

 .Pp
 Examples:
 .D1 \&.Ad [0,$]
 .D1 \&.Ad 0x00000000
 .Ss \&An
 Author name.
 .Pp
 Examples:
 .D1 \&.Ad [0,$]
 .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
+Requires either the name of an author or one of the following arguments:
+.Pp
+.Bl -tag -width "-nosplitX" -offset indent -compact

 .It Fl split
 .It Fl split

-Renders a line break before each author listing.
+Start a new output line before each subsequent invocation of
+.Sx \&An .

 .It Fl nosplit
 The opposite of
 .Fl split .
 .El
 .Pp
 .It Fl nosplit
 The opposite of
 .Fl split .
 .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
+The default is
+.Fl nosplit .
+The effect of selecting either of the

 .Fl split
 .Fl split

-will cause the first listing also to be split.
-If not in the AUTHORS section, the default is not to split.
+modes ends at the beginning of the
+.Em AUTHORS
+section.
+In the
+.Em AUTHORS
+section, the default is
+.Fl nosplit
+for the first author listing and
+.Fl split
+for all other author listings.

 .Pp
 Examples:
 .D1 \&.An -nosplit
 .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.
+.D1 \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv

 .Ss \&Ao
 .Ss \&Ao

-Begins a block enclosed by angled brackets.
+Begin a block enclosed by angle brackets.

 Does not have any head arguments.
 .Pp
 Examples:
 Does not have any head arguments.
 .Pp
 Examples:


@@ -976,14 +978,14 @@ Examples:
 See also
 .Sx \&Aq .
 .Ss \&Ap
 See also
 .Sx \&Aq .
 .Ss \&Ap

-Inserts an apostrophe without any surrounding white-space.
+Inserts an apostrophe without any surrounding whitespace.

 This is generally used as a grammatical device when referring to the verb
 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
+form of a function.
+.Pp
+Examples:
+.D1 \&.Fn execve \&Ap d

 .Ss \&Aq
 .Ss \&Aq

-Encloses its arguments in angled brackets.
+Encloses its arguments in angle brackets.

 .Pp
 Examples:
 .D1 \&.Fl -key= \&Ns \&Aq \&Ar val
 .Pp
 Examples:
 .D1 \&.Fl -key= \&Ns \&Aq \&Ar val


@@ -1003,7 +1005,7 @@ See also
 .Ss \&Ar
 Command arguments.
 If an argument is not provided, the string
 .Ss \&Ar
 Command arguments.
 If an argument is not provided, the string

-.Dq file ...
+.Dq file ...\&

 is used as a default.
 .Pp
 Examples:
 is used as a default.
 .Pp
 Examples:


@@ -1012,17 +1014,18 @@ Examples:
 .D1 \&.Ar arg1 , arg2 .
 .Ss \&At
 Formats an AT&T version.
 .D1 \&.Ar arg1 , arg2 .
 .Ss \&At
 Formats an AT&T version.

-Accepts at most one parameter:
-.Bl -tag -width 12n -offset indent
+Accepts one optional argument:
+.Pp
+.Bl -tag -width "v[1-7] | 32vX" -offset indent -compact

 .It Cm v[1-7] | 32v
 A version of
 .At .
 .It Cm V[.[1-4]]?
 .It Cm v[1-7] | 32v
 A version of
 .At .
 .It Cm V[.[1-4]]?

-A system version of
-.At .
+A version of
+.At V .

 .El
 .Pp
 .El
 .Pp

-Note that these parameters do not begin with a hyphen.
+Note that these arguments do not begin with a hyphen.

 .Pp
 Examples:
 .D1 \&.At
 .Pp
 Examples:
 .D1 \&.At


@@ -1038,82 +1041,93 @@ See also
 and
 .Sx \&Ux .
 .Ss \&Bc
 and
 .Sx \&Ux .
 .Ss \&Bc

-Closes a
+Close a

 .Sx \&Bo
 .Sx \&Bo

-block.  Does not have any tail arguments.
+block.
+Does not have any tail arguments.

 .Ss \&Bd
 .Ss \&Bd

-Begins a display block.
+Begin a display block.

 Its syntax is as follows:
 .Bd -ragged -offset indent
 .Pf \. Sx \&Bd
 Its syntax is as follows:
 .Bd -ragged -offset indent
 .Pf \. Sx \&Bd

-.Fl type
+.Fl Ns Ar type

 .Op Fl offset Ar width
 .Op Fl compact
 .Ed
 .Pp
 .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.
+Display blocks are used to select a different indentation and
+justification than the one used by the surrounding text.
+They may contain both macro lines and free-form text lines.
+By default, a display block is preceded by a vertical space.

 .Pp
 .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.
+The
+.Ar type
+must be one of the following:
+.Bl -tag -width 13n -offset indent
+.It Fl centered
+Centre-justify each line.
+Using this display type is not recommended; many
+.Nm
+implementations render it poorly.

 .It Fl filled
 Left- and right-justify the block.
 .It Fl literal
 .It Fl filled
 Left- and right-justify the block.
 .It Fl literal

-Alias for
-.Fl unfilled .
-.It Fl centered
-Centre-justify each line.
+Do not justify the block at all.
+Preserve white space as it appears in the input.
+.It Fl ragged
+Only left-justify the block.
+.It Fl unfilled
+An alias for
+.Fl literal .

 .El
 .Pp
 .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:
+The
+.Ar type
+must be provided first.
+Additional arguments may follow:
+.Bl -tag -width 13n -offset indent
+.It Fl offset Ar width
+Indent the display by the
+.Ar width ,
+which may be one of the following:

 .Bl -item
 .It
 .Bl -item
 .It

-As one of the pre-defined strings
-.Ar indent ,
+One of the pre-defined strings
+.Cm indent ,

 the width of standard indentation;
 the width of standard indentation;

-.Ar indent-two ,
+.Cm indent-two ,

 twice
 twice

-.Ar indent ;
-.Ar left ,
+.Cm indent ;
+.Cm left ,

 which has no effect;
 which has no effect;

-.Ar right ,
-which justifies to the right margin; and
-.Ar center ,
+.Cm right ,
+which justifies to the right margin; or
+.Cm center ,

 which aligns around an imagined centre axis.
 .It
 which aligns around an imagined centre axis.
 .It

-As a precalculated width for a named macro.
+A macro invocation, which selects a predefined width
+associated with that macro.

 The most popular is the imaginary macro
 .Ar \&Ds ,
 which resolves to
 The most popular is the imaginary macro
 .Ar \&Ds ,
 which resolves to

-.Ar 6n .
+.Sy 6n .

 .It
 .It

-As a scaling unit following the syntax described in
+A width using the syntax described in

 .Sx Scaling Widths .
 .It
 .Sx Scaling Widths .
 .It

-As the calculated string length of the opaque string.
+An arbitrary string, which indents by the length of this string.

 .El
 .Pp
 .El
 .Pp

-If not provided an argument, it will be ignored.
+When the argument is missing,
+.Fl offset
+is ignored.

 .It Fl compact
 .It Fl compact

-Do not assert a vertical space before the block.
+Do not assert vertical space before the display.

 .El
 .Pp
 Examples:
 .Bd -literal -offset indent
 .El
 .Pp
 Examples:
 .Bd -literal -offset indent

-\&.Bd \-unfilled \-offset two-indent \-compact
+\&.Bd \-literal \-offset indent \-compact

    Hello       world.
 \&.Ed
 .Ed
    Hello       world.
 \&.Ed
 .Ed


@@ -1140,7 +1154,7 @@ and
 argument are equivalent, as are
 .Fl symbolic
 and
 argument are equivalent, as are
 .Fl symbolic
 and

-.Cm \&Sy,
+.Cm \&Sy ,

 and
 .Fl literal
 and
 and
 .Fl literal
 and


@@ -1154,21 +1168,22 @@ is encountered.
 See also
 .Sx \&Li ,
 .Sx \&Ef ,
 See also
 .Sx \&Li ,
 .Sx \&Ef ,

+.Sx \&Em ,

 and
 .Sx \&Sy .
 .Ss \&Bk
 and
 .Sx \&Sy .
 .Ss \&Bk

-Begins a collection of macros or text not breaking the line.
-Its syntax is as follows:
+Keep the output generated from each macro input line together
+on one single output line.
+Line breaks in free-form text lines are unaffected.
+The syntax is as follows:

 .Pp
 .D1 Pf \. Sx \&Bk Fl words
 .Pp
 .Pp
 .D1 Pf \. Sx \&Bk Fl words
 .Pp

-Subsequent arguments are ignored.

 The
 .Fl words
 The
 .Fl words

-argument is required.
+argument is required; additional arguments are ignored.

 .Pp
 .Pp

-Each line within a keep block is kept intact, so the following example
-will not break within each
+The following example will not break within each

 .Sx \&Op
 macro line:
 .Bd -literal -offset indent
 .Sx \&Op
 macro line:
 .Bd -literal -offset indent


@@ -1181,128 +1196,132 @@ macro line:
 Be careful in using over-long lines within a keep block!
 Doing so will clobber the right margin.
 .Ss \&Bl
 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:
+Begin a list.
+Lists consist of items started by the
+.Sx \&It
+macro, containing a head or a body or both.
+The list syntax is as follows:

 .Bd -ragged -offset indent
 .Pf \. Sx \&Bl
 .Bd -ragged -offset indent
 .Pf \. Sx \&Bl

-.Fl type
+.Fl Ns Ar type

 .Op Fl width Ar val
 .Op Fl offset Ar val
 .Op Fl compact
 .Op HEAD ...
 .Ed
 .Pp
 .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
+The list
+.Ar type
+is mandatory and must be specified first.
+The
+.Fl width
+and
+.Fl offset
+arguments accept

 .Sx Scaling Widths
 .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).
+or use the length of the given string.
+The
+.Fl offset
+is a global indentation for the whole list, affecting both item heads
+and bodies.
+For those list types supporting it, the
+.Fl width
+argument requests an additional indentation of item bodies,
+to be added to the
+.Fl offset .
+Unless the
+.Fl compact
+argument is specified, list entries are separated by vertical space.
+.Pp

 A list must specify one of the following list types:
 .Bl -tag -width 12n -offset indent
 .It Fl bullet
 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
+No item heads can be specified, but a bullet will be printed at the head
+of each item.
+Item bodies start on the same output line as the bullet
+and are indented according to the

 .Fl width
 .Fl width

-argument varies the width of list bodies' left-margins.
+argument.

 .It Fl column
 A columnated list.
 The
 .Fl width
 .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
+argument has no effect; instead, each argument specifies the width
+of one column, using either the

 .Sx Scaling Widths
 .Sx Scaling Widths

-or literal text.
-If the initial macro of a
+syntax or the string length of the argument.
+If the first line of the body of a

 .Fl column
 list is not an
 .Fl column
 list is not an

-.Sx \&It ,
-an

 .Sx \&It
 .Sx \&It

-context spanning each line is implied until an
+macro line,

 .Sx \&It
 .Sx \&It

-line macro is encountered, at which point list bodies are interpreted as
+contexts spanning one input line each are implied until an
+.Sx \&It
+macro line is encountered, at which point items start being interpreted as

 described in the
 .Sx \&It
 documentation.
 .It Fl dash
 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.
+Like
+.Fl bullet ,
+except that dashes are used in place of bullets.

 .It Fl diag
 Like
 .Fl inset ,
 .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.
+except that item heads are not parsed for macro invocations.
+.\" but with additional formatting to the head.

 .It Fl enum
 .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.
+A numbered list.
+Formatted like
+.Fl bullet ,
+except that cardinal numbers are used in place of bullets,
+starting at 1.

 .It Fl hang
 Like
 .Fl tag ,
 .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.
+except that the first lines of item bodies are not indented, but follow
+the item heads like in
+.Fl inset
+lists.

 .It Fl hyphen
 Synonym for
 .Fl dash .
 .It Fl inset
 .It Fl hyphen
 Synonym for
 .Fl dash .
 .It Fl inset

-List bodies follow the list head.
-The
+Item bodies follow items heads on the same line, using normal inter-word
+spacing.
+Bodies are not indented, and the

 .Fl width
 argument is ignored.
 .It Fl item
 .Fl width
 argument is ignored.
 .It Fl item

-This produces blocks of text.
-The head of list entries must be empty.
-The
+No item heads can be specified, and none are printed.
+Bodies are not indented, and the

 .Fl width
 argument is ignored.
 .It Fl ohang
 .Fl width
 argument is ignored.
 .It Fl ohang

-List bodies are positioned on the line following the head.
+Item bodies start on the line following item heads and are not indented.

 The
 .Fl width
 argument is ignored.
 .It Fl tag
 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
+Item bodies are indented according to the

 .Fl width
 argument.
 .Fl width
 argument.

+When an item head fits inside the indentation, the item body follows
+this head on the same output line.
+Otherwise, the body starts on the output line following the head.

 .El
 .Pp
 See also
 .El
 .Pp
 See also

+.Sx \&El
+and

 .Sx \&It .
 .Ss \&Bo
 .Sx \&It .
 .Ss \&Bo

-Begins a block enclosed by square brackets.
+Begin a block enclosed by square brackets.

 Does not have any head arguments.
 .Pp
 Examples:
 Does not have any head arguments.
 .Pp
 Examples:

-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact

 \&.Bo 1 ,
 \&.Dv BUFSIZ \&Bc
 .Ed
 \&.Bo 1 ,
 \&.Dv BUFSIZ \&Bc
 .Ed


@@ -1326,15 +1345,16 @@ and
 See also
 .Sx \&Bo .
 .Ss \&Brc
 See also
 .Sx \&Bo .
 .Ss \&Brc

-Closes a
+Close a

 .Sx \&Bro
 .Sx \&Bro

-block.  Does not have any tail arguments.
+block.
+Does not have any tail arguments.

 .Ss \&Bro
 .Ss \&Bro

-Begins a block enclosed by curly braces.
+Begin a block enclosed by curly braces.

 Does not have any head arguments.
 .Pp
 Examples:
 Does not have any head arguments.
 .Pp
 Examples:

-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact

 \&.Bro 1 , ... ,
 \&.Va n \&Brc
 .Ed
 \&.Bro 1 , ... ,
 \&.Va n \&Brc
 .Ed


@@ -1368,7 +1388,7 @@ and
 .Sx \&Ux .
 .Ss \&Bt
 Prints
 .Sx \&Ux .
 .Ss \&Bt
 Prints

-.Dq is currently in beta test.
+.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.
 .Ss \&Bx
 Format the BSD version provided as an argument, or a default value if no
 argument is provided.


@@ -1387,7 +1407,7 @@ See also
 and
 .Sx \&Ux .
 .Ss \&Cd
 and
 .Sx \&Ux .
 .Ss \&Cd

-Configuration declaration.
+Kernel configuration declaration.

 This denotes strings accepted by
 .Xr config 8 .
 .Pp
 This denotes strings accepted by
 .Xr config 8 .
 .Pp


@@ -1396,7 +1416,7 @@ Examples:
 .Pp
 .Em Remarks :
 this macro is commonly abused by using quoted literals to retain
 .Pp
 .Em Remarks :
 this macro is commonly abused by using quoted literals to retain

-white-space and align consecutive
+whitespace and align consecutive

 .Sx \&Cd
 declarations.
 This practise is discouraged.
 .Sx \&Cd
 declarations.
 This practise is discouraged.


@@ -1424,15 +1444,18 @@ See also
 and
 .Sx \&Dl .
 .Ss \&Db
 and
 .Sx \&Dl .
 .Ss \&Db

-Start a debugging context.
-This macro is parsed, but generally ignored.
+Switch debugging mode.

 Its syntax is as follows:
 .Pp
 .D1 Pf \. Sx \&Db Cm on | off
 Its syntax is as follows:
 .Pp
 .D1 Pf \. Sx \&Db Cm on | off

+.Pp
+This macro is ignored by
+.Xr mandoc 1 .

 .Ss \&Dc
 .Ss \&Dc

-Closes a
+Close a

 .Sx \&Do
 .Sx \&Do

-block.  Does not have any tail arguments.
+block.
+Does not have any tail arguments.

 .Ss \&Dd
 Document date.
 This is the mandatory first macro of any
 .Ss \&Dd
 Document date.
 This is the mandatory first macro of any


@@ -1440,17 +1463,17 @@ This is the mandatory first macro of any
 manual.
 Its syntax is as follows:
 .Pp
 manual.
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&Dd Cm date
+.D1 Pf \. Sx \&Dd Op Ar date

 .Pp
 The
 .Pp
 The

-.Cm date
-field may be either
+.Ar date
+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 .
 .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.
+If a date does not conform or is empty, the current date is used.

 .Pp
 Examples:
 .D1 \&.Dd $\&Mdocdate$
 .Pp
 Examples:
 .D1 \&.Dd $\&Mdocdate$


@@ -1468,23 +1491,30 @@ invocations.
 It is followed by a newline.
 .Pp
 Examples:
 It is followed by a newline.
 .Pp
 Examples:

-.D1 \&.Dl % mandoc mdoc.7 | less
+.D1 \&.Dl % mandoc mdoc.7 \e(ba less

 .Pp
 See also
 .Sx \&Bd
 and
 .Sx \&D1 .
 .Ss \&Do
 .Pp
 See also
 .Sx \&Bd
 and
 .Sx \&D1 .
 .Ss \&Do

-Begins a block enclosed by double quotes.  Does not have any head
-arguments.
+Begin a block enclosed by double quotes.
+Does not have any head arguments.

 .Pp
 Examples:
 .Pp
 Examples:

-.D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot
+.Bd -literal -offset indent -compact
+\&.Do
+April is the cruellest month
+\&.Dc
+\e(em T.S. Eliot
+.Ed

 .Pp
 See also
 .Sx \&Dq .
 .Ss \&Dq
 .Pp
 See also
 .Sx \&Dq .
 .Ss \&Dq

-Encloses its arguments in double quotes.
+Encloses its arguments in
+.Dq typographic
+double-quotes.

 .Pp
 Examples:
 .Bd -literal -offset indent -compact
 .Pp
 Examples:
 .Bd -literal -offset indent -compact


@@ -1493,6 +1523,9 @@ Examples:
 .Ed
 .Pp
 See also
 .Ed
 .Pp
 See also

+.Sx \&Qq ,
+.Sx \&Sq ,
+and

 .Sx \&Do .
 .Ss \&Dt
 Document title.
 .Sx \&Do .
 .Ss \&Dt
 Document title.


@@ -1503,22 +1536,22 @@ Its syntax is as follows:
 .Bd -ragged -offset indent
 .Pf \. Sx \&Dt
 .Oo
 .Bd -ragged -offset indent
 .Pf \. Sx \&Dt
 .Oo

-.Cm title
+.Ar title

 .Oo
 .Oo

-.Cm section
-.Op Cm volume | arch
+.Ar section
+.Op Ar volume | arch

 .Oc
 .Oc
 .Ed
 .Pp
 Its arguments are as follows:
 .Bl -tag -width Ds -offset Ds
 .Oc
 .Oc
 .Ed
 .Pp
 Its arguments are as follows:
 .Bl -tag -width Ds -offset Ds

-.It Cm title
+.It Ar title

 The document's title (name), defaulting to
 The document's title (name), defaulting to

-.Qq UNKNOWN
+.Dq UNKNOWN

 if unspecified.
 It should be capitalised.
 if unspecified.
 It should be capitalised.

-.It Cm section
+.It Ar section

 The manual section.
 This may be one of
 .Ar 1
 The manual section.
 This may be one of
 .Ar 1


@@ -1555,9 +1588,9 @@ or
 .Ar paper
 .Pq paper .
 It should correspond to the manual's filename suffix and defaults to
 .Ar paper
 .Pq paper .
 It should correspond to the manual's filename suffix and defaults to

-.Qq 1
+.Dq 1

 if unspecified.
 if unspecified.

-.It Cm volume
+.It Ar volume

 This overrides the volume inferred from
 .Ar section .
 This field is optional, and if specified, must be one of
 This overrides the volume inferred from
 .Ar section .
 This field is optional, and if specified, must be one of


@@ -1586,10 +1619,10 @@ This field is optional, and if specified, must be one of
 or
 .Ar CON
 .Pq contributed manuals .
 or
 .Ar CON
 .Pq contributed manuals .

-.It Cm arch
+.It Ar arch

 This specifies a specific relevant architecture.
 If
 This specifies a specific relevant architecture.
 If

-.Cm volume
+.Ar volume

 is not provided, it may be used in its place, else it may be used
 subsequent that.
 It, too, is optional.
 is not provided, it may be used in its place, else it may be used
 subsequent that.
 It, too, is optional.


@@ -1664,10 +1697,10 @@ Close a scope started by
 .Sx \&Eo .
 Its syntax is as follows:
 .Pp
 .Sx \&Eo .
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&Ec Op Cm TERM
+.D1 Pf \. Sx \&Ec Op Ar TERM

 .Pp
 The
 .Pp
 The

-.Cm TERM
+.Ar TERM

 argument is used as the enclosure tail, for example, specifying \e(rq
 will emulate
 .Sx \&Dc .
 argument is used as the enclosure tail, for example, specifying \e(rq
 will emulate
 .Sx \&Dc .


@@ -1675,13 +1708,13 @@ will emulate
 End a display context started by
 .Sx \&Bd .
 .Ss \&Ef
 End a display context started by
 .Sx \&Bd .
 .Ss \&Ef

-Ends a font mode context started by
+End a font mode context started by

 .Sx \&Bf .
 .Ss \&Ek
 .Sx \&Bf .
 .Ss \&Ek

-Ends a keep context started by
+End a keep context started by

 .Sx \&Bk .
 .Ss \&El
 .Sx \&Bk .
 .Ss \&El

-Ends a list context started by
+End a list context started by

 .Sx \&Bl .
 .Pp
 See also
 .Sx \&Bl .
 .Pp
 See also


@@ -1696,16 +1729,23 @@ stylistically decorating technical terms.
 Examples:
 .D1 \&.Em Warnings!
 .D1 \&.Em Remarks :
 Examples:
 .D1 \&.Em Warnings!
 .D1 \&.Em Remarks :

+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Sy ,
+and
+.Sx \&Li .

 .Ss \&En
 .Ss \&En

-This macro is obsolete and not implemented.
+This macro is obsolete and not implemented in
+.Xr mandoc 1 .

 .Ss \&Eo
 An arbitrary enclosure.
 Its syntax is as follows:
 .Pp
 .Ss \&Eo
 An arbitrary enclosure.
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&Eo Op Cm TERM
+.D1 Pf \. Sx \&Eo Op Ar TERM

 .Pp
 The
 .Pp
 The

-.Cm TERM
+.Ar TERM

 argument is used as the enclosure head, for example, specifying \e(lq
 will emulate
 .Sx \&Do .
 argument is used as the enclosure head, for example, specifying \e(lq
 will emulate
 .Sx \&Do .


@@ -1728,16 +1768,19 @@ Examples:
 .D1 \&.Ev DISPLAY
 .D1 \&.Ev PATH
 .Ss \&Ex
 .D1 \&.Ev DISPLAY
 .D1 \&.Ev PATH
 .Ss \&Ex

-Inserts text regarding a utility's exit values.
-This macro must have first the
-.Fl std
-argument specified, then an optional
-.Ar utility .
-If
+Insert a standard sentence regarding exit values.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ex Fl std Op Ar utility
+.Pp
+When

 .Ar utility
 .Ar utility

-is not provided, the document's name as stipulated in
+is not specified, the document's name set by

 .Sx \&Nm
 .Sx \&Nm

-is provided.
+is used.
+.Pp
+See also
+.Sx \&Rv .

 .Ss \&Fa
 Function argument.
 Its syntax is as follows:
 .Ss \&Fa
 Function argument.
 Its syntax is as follows:


@@ -1770,7 +1813,7 @@ Examples:
 See also
 .Sx \&Fo .
 .Ss \&Fc
 See also
 .Sx \&Fo .
 .Ss \&Fc

-Ends a function context started by
+End a function context started by

 .Sx \&Fo .
 .Ss \&Fd
 Historically used to document include files.
 .Sx \&Fo .
 .Ss \&Fd
 Historically used to document include files.


@@ -1857,6 +1900,7 @@ See also
 .Sx \&Fa ,
 .Sx \&Fc ,
 and
 .Sx \&Fa ,
 .Sx \&Fc ,
 and

+.Sx \&Ft .

 .Ss \&Ft
 A function type.
 Its syntax is as follows:
 .Ss \&Ft
 A function type.
 Its syntax is as follows:


@@ -1876,7 +1920,9 @@ See also
 and
 .Sx \&Fo .
 .Ss \&Fx
 and
 .Sx \&Fo .
 .Ss \&Fx

-Format the FreeBSD version provided as an argument, or a default value
+Format the
+.Fx
+version provided as an argument, or a default value

 if no argument is provided.
 .Pp
 Examples:
 if no argument is provided.
 .Pp
 Examples:


@@ -1905,7 +1951,7 @@ Examples:
 .D1 \&.Ic alias
 .Pp
 Note that using
 .D1 \&.Ic alias
 .Pp
 Note that using

-.Sx \&Bd No Fl literal
+.Sx \&Bd Fl literal

 or
 .Sx \&D1
 is preferred for displaying code; the
 or
 .Sx \&D1
 is preferred for displaying code; the


@@ -1913,14 +1959,14 @@ is preferred for displaying code; the
 macro is used when referring to specific instructions.
 .Ss \&In
 An
 macro is used when referring to specific instructions.
 .Ss \&In
 An

-.Qq include
+.Dq include

 file.
 In the
 .Em SYNOPSIS
 section (only if invoked as the line macro), the first argument is
 preceded by
 file.
 In the
 .Em SYNOPSIS
 section (only if invoked as the line macro), the first argument is
 preceded by

-.Qq #include ,
-the arguments is enclosed in angled braces.
+.Dq #include ,
+the arguments is enclosed in angle brackets.

 .Pp
 Examples:
 .D1 \&.In sys/types
 .Pp
 Examples:
 .D1 \&.In sys/types


@@ -1991,8 +2037,8 @@ 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
 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
+interpreted as a macro).
+Note that the tab phrase delimiter may only be used within the

 .Sx \&It
 line itself.
 Subsequent this, only the
 .Sx \&It
 line itself.
 Subsequent this, only the


@@ -2036,6 +2082,12 @@ Examples:
 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.
 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:
 .Ss \&Lk
 Format a hyperlink.
 Its syntax is as follows:


@@ -2043,7 +2095,7 @@ Its syntax is as follows:
 .D1 Pf \. Sx \&Lk Cm uri Op Cm name
 .Pp
 Examples:
 .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 \*qThe BSD.lv Project\*q

 .D1 \&.Lk http://bsd.lv
 .Pp
 See also
 .D1 \&.Lk http://bsd.lv
 .Pp
 See also


@@ -2052,9 +2104,17 @@ See also
 Synonym for
 .Sx \&Pp .
 .Ss \&Ms
 Synonym for
 .Sx \&Pp .
 .Ss \&Ms

+Display a mathematical symbol.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ms Cm symbol
+.Pp
+Examples:
+.D1 \&.Ms sigma
+.D1 \&.Ms aleph

 .Ss \&Mt
 Format a
 .Ss \&Mt
 Format a

-.Qq mailto:
+.Dq mailto:

 hyperlink.
 Its syntax is as follows:
 .Pp
 hyperlink.
 Its syntax is as follows:
 .Pp


@@ -2063,7 +2123,7 @@ Its syntax is as follows:
 Examples:
 .D1 \&.Mt discuss@manpages.bsd.lv
 .Ss \&Nd
 Examples:
 .D1 \&.Mt discuss@manpages.bsd.lv
 .Ss \&Nd

-A one-line description of the manual's content.
+A one line description of the manual's content.

 This may only be invoked in the
 .Em SYNOPSIS
 section subsequent the
 This may only be invoked in the
 .Em SYNOPSIS
 section subsequent the


@@ -2125,14 +2185,27 @@ macro rather than
 to mark up the name of the manual page.
 .Ss \&No
 A
 to mark up the name of the manual page.
 .Ss \&No
 A

-.Qq noop
+.Dq noop

 macro used to terminate prior macro contexts.
 .Pp
 Examples:
 .D1 \&.Sx \&Fl ab \&No cd \&Fl ef
 .Ss \&Ns
 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
 .Ss \&Nx

-Format the NetBSD version provided as an argument, or a default value if
+Format the
+.Nx
+version provided as an argument, or a default value if

 no argument is provided.
 .Pp
 Examples:
 no argument is provided.
 .Pp
 Examples:


@@ -2149,7 +2222,7 @@ See also
 and
 .Sx \&Ux .
 .Ss \&Oc
 and
 .Sx \&Ux .
 .Ss \&Oc

-Closes multi-line
+Close multi-line

 .Sx \&Oo
 context.
 .Ss \&Oo
 .Sx \&Oo
 context.
 .Ss \&Oo


@@ -2157,7 +2230,7 @@ Multi-line version of
 .Sx \&Op .
 .Pp
 Examples:
 .Sx \&Op .
 .Pp
 Examples:

-.Bd -literal -offset indent
+.Bd -literal -offset indent -compact

 \&.Oo
 \&.Op Fl flag Ns Ar value
 \&.Oc
 \&.Oo
 \&.Op Fl flag Ns Ar value
 \&.Oc


@@ -2181,7 +2254,7 @@ any
 file.
 Its syntax is as follows:
 .Pp
 file.
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&Os Op Cm system
+.D1 Pf \. Sx \&Os Op Cm system Op Cm version

 .Pp
 The optional
 .Cm system
 .Pp
 The optional
 .Cm system


@@ -2204,7 +2277,9 @@ Unknown usage.
 .Em Remarks :
 this macro has been deprecated.
 .Ss \&Ox
 .Em Remarks :
 this macro has been deprecated.
 .Ss \&Ox

-Format the OpenBSD version provided as an argument, or a default value
+Format the
+.Ox
+version provided as an argument, or a default value

 if no argument is provided.
 .Pp
 Examples:
 if no argument is provided.
 .Pp
 Examples:


@@ -2234,7 +2309,7 @@ Close parenthesised context opened by
 .Sx \&Po .
 .Ss \&Pf
 Removes the space
 .Sx \&Po .
 .Ss \&Pf
 Removes the space

-.Pq Qq prefix
+.Pq Dq prefix

 between its arguments.
 Its syntax is as follows:
 .Pp
 between its arguments.
 Its syntax is as follows:
 .Pp


@@ -2259,16 +2334,36 @@ Parenthesised enclosure.
 See also
 .Sx \&Po .
 .Ss \&Qc
 See also
 .Sx \&Po .
 .Ss \&Qc

+Close quoted context opened by
+.Sx \&Qo .

 .Ss \&Ql
 .Ss \&Ql

+Format a single-quoted literal.
+See also
+.Sx \&Qq
+and
+.Sx \&Sq .

 .Ss \&Qo
 .Ss \&Qo

+Multi-line version of
+.Sx \&Qq .

 .Ss \&Qq
 .Ss \&Qq

+Encloses its arguments in
+.Dq typewriter
+double-quotes.
+Consider using
+.Sx \&Dq .
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Sq ,
+and
+.Sx \&Qo .

 .Ss \&Re
 .Ss \&Re

-Closes a
+Close an

 .Sx \&Rs
 block.
 Does not have any tail arguments.
 .Ss \&Rs
 .Sx \&Rs
 block.
 Does not have any tail arguments.
 .Ss \&Rs

-Begins a bibliographic
+Begin a bibliographic

 .Pq Dq reference
 block.
 Does not have any head arguments.
 .Pq Dq reference
 block.
 Does not have any head arguments.


@@ -2308,8 +2403,37 @@ 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
 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
 .Ss \&Sc

+Close single-quoted context opened by
+.Sx \&So .

 .Ss \&Sh
 .Ss \&Sh

+Begin a new section.
+For a list of conventional manual sections, see
+.Sx MANUAL STRUCTURE .
+These sections should be used unless it's absolutely necessary that
+custom sections be used.
+.Pp
+Section names should be unique so that they may be keyed by
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Ss ,
+and
+.Sx \&Sx .

 .Ss \&Sm
 Switches the spacing mode for output generated from macros.
 Its syntax is as follows:
 .Ss \&Sm
 Switches the spacing mode for output generated from macros.
 Its syntax is as follows:


@@ -2324,15 +2448,158 @@ 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
 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
 .Ss \&Sq

+Encloses its arguments in
+.Dq typewriter
+single-quotes.
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Qq ,
+and
+.Sx \&So .

 .Ss \&Ss
 .Ss \&Ss

+Begin a new sub-section.
+Unlike with
+.Sx \&Sh ,
+there's no convention for sub-sections.
+Conventional sections, as described in
+.Sx MANUAL STRUCTURE ,
+rarely have sub-sections.
+.Pp
+Sub-section names should be unique so that they may be keyed by
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Sh ,
+and
+.Sx \&Sx .

 .Ss \&St
 .Ss \&St

+Replace an abbreviation for a standard with the full form.
+The following standards are recognised:
+.Pp
+.Bl -tag -width "-p1003.1g-2000X" -compact
+.It \-p1003.1-88
+.St -p1003.1-88
+.It \-p1003.1-90
+.St -p1003.1-90
+.It \-p1003.1-96
+.St -p1003.1-96
+.It \-p1003.1-2001
+.St -p1003.1-2001
+.It \-p1003.1-2004
+.St -p1003.1-2004
+.It \-p1003.1-2008
+.St -p1003.1-2008
+.It \-p1003.1
+.St -p1003.1
+.It \-p1003.1b
+.St -p1003.1b
+.It \-p1003.1b-93
+.St -p1003.1b-93
+.It \-p1003.1c-95
+.St -p1003.1c-95
+.It \-p1003.1g-2000
+.St -p1003.1g-2000
+.It \-p1003.1i-95
+.St -p1003.1i-95
+.It \-p1003.2-92
+.St -p1003.2-92
+.It \-p1003.2a-92
+.St -p1003.2a-92
+.It \-p1387.2-95
+.St -p1387.2-95
+.It \-p1003.2
+.St -p1003.2
+.It \-p1387.2
+.St -p1387.2
+.It \-isoC
+.St -isoC
+.It \-isoC-90
+.St -isoC-90
+.It \-isoC-amd1
+.St -isoC-amd1
+.It \-isoC-tcor1
+.St -isoC-tcor1
+.It \-isoC-tcor2
+.St -isoC-tcor2
+.It \-isoC-99
+.St -isoC-99
+.It \-iso9945-1-90
+.St -iso9945-1-90
+.It \-iso9945-1-96
+.St -iso9945-1-96
+.It \-iso9945-2-93
+.St -iso9945-2-93
+.It \-ansiC
+.St -ansiC
+.It \-ansiC-89
+.St -ansiC-89
+.It \-ansiC-99
+.St -ansiC-99
+.It \-ieee754
+.St -ieee754
+.It \-iso8802-3
+.St -iso8802-3
+.It \-ieee1275-94
+.St -ieee1275-94
+.It \-xpg3
+.St -xpg3
+.It \-xpg4
+.St -xpg4
+.It \-xpg4.2
+.St -xpg4.2
+.St -xpg4.3
+.It \-xbd5
+.St -xbd5
+.It \-xcu5
+.St -xcu5
+.It \-xsh5
+.St -xsh5
+.It \-xns5
+.St -xns5
+.It \-xns5.2
+.St -xns5.2
+.It \-xns5.2d2.0
+.St -xns5.2d2.0
+.It \-xcurses4.2
+.St -xcurses4.2
+.It \-susv2
+.St -susv2
+.It \-susv3
+.St -susv3
+.It \-svid4
+.St -svid4
+.El

 .Ss \&Sx
 .Ss \&Sx

+Reference a section or sub-section.
+The referenced section or sub-section name must be identical to the
+enclosed argument, including whitespace.
+.Pp
+Examples:
+.D1 \&.Sx MANUAL STRUCTURE

 .Ss \&Sy
 .Ss \&Sy

+Format enclosed arguments in symbolic
+.Pq Dq boldface .
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Li ,
+and
+.Sx \&Em .

 .Ss \&Tn
 .Ss \&Tn

+Format a tradename.
+.Pp
+Examples:
+.D1 \&.Tn IBM

 .Ss \&Ud
 Prints out
 .Ss \&Ud
 Prints out

-.Dq currently under development.
+.Dq currently under development .

 .Ss \&Ux
 Format the UNIX name.
 Accepts no argument.
 .Ss \&Ux
 Format the UNIX name.
 Accepts no argument.


@@ -2405,14 +2672,35 @@ is followed by non-punctuation, an
 .Sx \&Ns
 is inserted into the token stream.
 This behaviour is for compatibility with
 .Sx \&Ns
 is inserted into the token stream.
 This behaviour is for compatibility with

-.Xr groff 1 .
+GNU troff.

 .Pp
 Examples:
 .D1 \&.Xr mandoc 1
 .D1 \&.Xr mandoc 1 \&;
 .D1 \&.Xr mandoc 1 \&Ns s behaviour
 .Ss \&br
 .Pp
 Examples:
 .D1 \&.Xr mandoc 1
 .D1 \&.Xr mandoc 1 \&;
 .D1 \&.Xr mandoc 1 \&Ns s behaviour
 .Ss \&br

+Emits a line-break.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+.Pp
+Consider using
+.Sx \&Pp
+in the event of natural paragraph breaks.

 .Ss \&sp
 .Ss \&sp

+Emits vertical space.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&sp Op Cm height
+.Pp
+The
+.Cm height
+argument must be formatted as described in
+.Sx Scaling Widths .
+If unspecified,
+.Sx \&sp
+asserts a single vertical space.

 .Sh COMPATIBILITY
 This section documents compatibility between mandoc and other other
 troff implementations, at this time limited to GNU troff
 .Sh COMPATIBILITY
 This section documents compatibility between mandoc and other other
 troff implementations, at this time limited to GNU troff


@@ -2427,215 +2715,168 @@ file re-write
 Heirloom troff, the other significant troff implementation accepting
 \-mdoc, is similar to historic groff.
 .Pp
 Heirloom troff, the other significant troff implementation accepting
 \-mdoc, is similar to historic groff.
 .Pp

+The following problematic behaviour is found in groff:
+.ds hist (Historic groff only.)
+.Pp

 .Bl -dash -compact
 .It
 .Bl -dash -compact
 .It

-The \es (font size), \em (font colour), and \eM (font filling colour)
-font decoration escapes are all discarded in mandoc.
+.Sx \&At
+with unknown arguments produces no output at all.
+\*[hist]
+Newer groff and mandoc print
+.Qq AT&T UNIX
+and the arguments.

 .It
 .It

-Old groff fails to assert a newline before
-.Sx \&Bd Fl ragged compact .
+.Sx \&Bd Fl column
+does not recognize trailing punctuation characters when they immediately
+precede tabulator characters, but treats them as normal text and
+outputs a space before them.
+.It
+.Sx \&Bd Fl ragged compact
+does not start a new line.
+\*[hist]
+.It
+.Sx \&Dd
+without an argument prints
+.Dq Epoch .
+In mandoc, it resolves to the current date.
+.It
+.Sx \&Fl
+does not print a dash for an empty argument.
+\*[hist]
+.It
+.Sx \&Fn
+does not start a new line unless invoked as the line macro in the
+.Em SYNOPSIS
+section.
+\*[hist]

 .It
 .It

-groff behaves inconsistently when encountering
-.Pf non- Sx \&Fa
-children of

 .Sx \&Fo
 .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.
+with
+.Pf non- Sx \&Fa
+children causes inconsistent spacing between arguments.
+In mandoc, a single space is always inserted between arguments.

 .It
 .It

-groff behaves inconsistently when encountering

 .Sx \&Ft
 .Sx \&Ft

-and
-.Sx \&Fn

 in the
 in the

-.Em SYNOPSIS :
-at times newline(s) are suppressed depending on whether a prior
+.Em SYNOPSIS
+causes inconsistent vertical spacing, depending on whether a prior

 .Sx \&Fn
 has been invoked.
 .Sx \&Fn
 has been invoked.

-In mandoc, this is not the case.

 See
 .Sx \&Ft
 and
 .Sx \&Fn
 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.
+for the normalised behaviour in mandoc.

 .It
 .It

-Historic groff formats the

 .Sx \&In
 .Sx \&In

-badly: trailing arguments are trashed and
-.Em SYNOPSIS
-is not specially treated.
+ignores additional arguments and is not treated specially in the
+.Em SYNOPSIS .
+\*[hist]

 .It
 .It

-groff does not accept the
-.Sq \&Ta
-pseudo-macro as a line macro.
-mandoc does.
+.Sx \&It
+sometimes requires a
+.Fl nested
+flag.
+\*[hist]
+In new groff and mandoc, any list may be nested by default and
+.Fl enum
+lists will restart the sequence only for the sub-list.
+.It
+.Sx \&Li
+followed by a reserved character is incorrectly used in some manuals
+instead of properly quoting that character, which sometimes works with
+historic groff.

 .It
 .It

-The comment syntax
-.Sq \e\."
-is no longer accepted.
+.Sx \&Lk
+only accepts a single link-name argument; the remainder is misformatted.

 .It
 .It

-In groff, the

 .Sx \&Pa
 .Sx \&Pa

-macro does not format its arguments when used in the FILES section under
+does not format its arguments when used in the FILES section under

 certain list types.
 certain list types.

-mandoc does.

 .It
 .It

-Historic groff does not print a dash for empty
-.Sx \&Fl
-arguments.
-mandoc and newer groff implementations do.
+.Sx \&Ta
+can only be called by other macros, but not at the beginning of a line.
+.It
+.Sx \&%C
+is not implemented.
+.It
+Historic groff has many un-callable macros.
+Most of these (excluding some block-level macros) are callable
+in new groff and mandoc.
+.It
+.Sq \(ba
+(vertical bar) is not fully supported as a delimiter.
+\*[hist]

 .It
 .It

-groff behaves irregularly when specifying

 .Sq \ef
 .Sq \ef

+.Pq font face
+and
+.Sq \ef
+.Pq font family face

 .Sx Text Decoration
 .Sx Text Decoration

-within line-macro scopes.
-mandoc follows a consistent system.
+escapes behave irregularly when specified within line-macro scopes.

 .It
 .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.
+Negative scaling units return to prior lines.
+Instead, mandoc truncates them to zero.
+.El
+.Pp
+The following features are unimplemented in mandoc:
+.Pp
+.Bl -dash -compact

 .It
 .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.
+.Sx \&Bd
+.Fl file Ar file .

 .It
 .It

-Display offsets

 .Sx \&Bd
 .Fl offset Ar center
 and
 .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.
+.Fl offset Ar right .
+Groff does not implement centered and flush-right rendering either,
+but produces large indentations.

 .It
 .It

-In groff, the
-.Sx \&Cd ,
-.Sx \&Er ,
-.Sx \&Ex ,
+The
+.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 ,

 and
 and

-.Sx \&Rv
-macros were stipulated only to occur in certain manual sections.
-mandoc does not have these restrictions.
+.Sq \es
+.Pq text size
+escape sequences are all discarded in mandoc.

 .It
 .It

-Newer groff and mandoc print
-.Qq AT&T UNIX
-prior to unknown arguments of
-.Sx \&At ;
-older groff did nothing.
+The
+.Sq \ef
+scaling unit is accepted by mandoc, but rendered as the default unit.
+.It
+In quoted literals, groff allows pairwise double-quotes to produce a
+standalone double-quote in formatted output.
+This is not supported by mandoc.

 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr mandoc_char 7
 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .Xr mandoc_char 7

+.Sh HISTORY
+The
+.Nm
+language first appeared as a troff macro package in
+.Bx 4.4 .
+It was later significantly updated by Werner Lemberg and Ruslan Ermilov
+in groff-1.20.1.
+The standalone implementation that is part of the
+.Xr mandoc 1
+utility written by Kristaps Dzonsons appeared in
+.Ox 4.6 .

 .Sh AUTHORS
 The
 .Nm
 reference was written by
 .An Kristaps Dzonsons Aq kristaps@bsd.lv .
 .Sh AUTHORS
 The
 .Nm
 reference was written by
 .An Kristaps Dzonsons Aq kristaps@bsd.lv .

-.\"
-.\" XXX: this really isn't the place for these caveats.
-.\" .
-.\" .
-.\" .Sh CAVEATS
-.\" There are many ambiguous parts of mdoc.
-.\" .
-.\" .Pp
-.\" .Bl -dash -compact
-.\" .It
-.\" .Sq \&Fa
-.\" should be
-.\" .Sq \&Va
-.\" as function arguments are variables.
-.\" .It
-.\" .Sq \&Ft
-.\" should be
-.\" .Sq \&Vt
-.\" as function return types are still types.  Furthermore, the
-.\" .Sq \&Ft
-.\" should be removed and
-.\" .Sq \&Fo ,
-.\" which ostensibly follows it, should follow the same convention as
-.\" .Sq \&Va .
-.\" .It
-.\" .Sq \&Va
-.\" should formalise that only one or two arguments are acceptable: a
-.\" variable name and optional, preceding type.
-.\" .It
-.\" .Sq \&Fd
-.\" is ambiguous.  It's commonly used to indicate an include file in the
-.\" synopsis section.
-.\" .Sq \&In
-.\" should be used, instead.
-.\" .It
-.\" Only the
-.\" .Sq \-literal
-.\" argument to
-.\" .Sq \&Bd
-.\" makes sense.  The remaining ones should be removed.
-.\" .It
-.\" The
-.\" .Sq \&Xo
-.\" and
-.\" .Sq \&Xc
-.\" macros should be deprecated.
-.\" .It
-.\" The
-.\" .Sq \&Dt
-.\" macro lacks clarity.  It should be absolutely clear which title will
-.\" render when formatting the manual page.
-.\" .It
-.\" A
-.\" .Sq \&Lx
-.\" should be provided for Linux (\(`a la
-.\" .Sq \&Ox ,
-.\" .Sq \&Nx
-.\" etc.).
-.\" .It
-.\" There's no way to refer to references in
-.\" .Sq \&Rs/Re
-.\" blocks.
-.\" .It
-.\" The \-split and \-nosplit dictates via
-.\" .Sq \&An
-.\" are re-set when entering and leaving the AUTHORS section.
-.\" .El
-.\" .