When a subsection header contains no letters but only special

[mandoc.git] / mdoc.7

diff --git a/mdoc.7 b/mdoc.7
index df25d8cbe42bdf081f28b847d06ea4bc9ec8786c..5c07434cd80e6d5baa70db10cd176977b27ec862 100644 (file)
--- a/mdoc.7
+++ b/mdoc.7
@@ -1,7 +1,7 @@
-.\"    $Id: mdoc.7,v 1.251 2015/02/15 17:57:45 schwarze Exp $
+.\"    $Id: mdoc.7,v 1.271 2018/07/28 18:34:15 schwarze Exp $

 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>

-.\" Copyright (c) 2010, 2011, 2013 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2010, 2011, 2013-2018 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
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above


@@ -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: February 15 2015 $
+.Dd $Mdocdate: July 28 2018 $

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


@@ -304,6 +304,11 @@ Print verbose information.
 \&.El
 .Ed
 .Pp
 \&.El
 .Ed
 .Pp

+List the options in alphabetical order,
+uppercase before lowercase for each letter and
+with no regard to whether an option takes an argument.
+Put digits in ascending order before all letter options.
+.Pp

 Manuals not documenting a command won't include the above fragment.
 .Pp
 Since the
 Manuals not documenting a command won't include the above fragment.
 .Pp
 Since the


@@ -471,10 +476,8 @@ in the alphabetical
 .It Sx \&Ap Ta apostrophe without surrounding whitespace (no arguments)
 .It Sx \&Sm Ta switch horizontal spacing mode: Op Cm on | off
 .It Sx \&Bk , \&Ek Ta keep block: Fl words
 .It Sx \&Ap Ta apostrophe without surrounding whitespace (no arguments)
 .It Sx \&Sm Ta switch horizontal spacing mode: Op Cm on | off
 .It Sx \&Bk , \&Ek Ta keep block: Fl words

-.It Sx \&br Ta force output line break in text mode (no arguments)
-.It Sx \&sp Ta force vertical space: Op Ar height

 .El
 .El

-.Ss Semantic markup for command line utilities:
+.Ss Semantic markup for command line utilities

 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&Nm Ta start a SYNOPSIS block with the name of a utility
 .It Sx \&Fl Ta command line options (flags) (>=0 arguments)
 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&Nm Ta start a SYNOPSIS block with the name of a utility
 .It Sx \&Fl Ta command line options (flags) (>=0 arguments)


@@ -485,7 +488,7 @@ in the alphabetical
 .It Sx \&Ev Ta environmental variable (>0 arguments)
 .It Sx \&Pa Ta file system path (>=0 arguments)
 .El
 .It Sx \&Ev Ta environmental variable (>0 arguments)
 .It Sx \&Pa Ta file system path (>=0 arguments)
 .El

-.Ss Semantic markup for function libraries:
+.Ss Semantic markup for function libraries

 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&Lb Ta function library (one argument)
 .It Sx \&In Ta include file (one argument)
 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&Lb Ta function library (one argument)
 .It Sx \&In Ta include file (one argument)


@@ -506,7 +509,7 @@ in the alphabetical
 .It Sx \&Er Ta error constant (>0 arguments)
 .It Sx \&Ev Ta environmental variable (>0 arguments)
 .El
 .It Sx \&Er Ta error constant (>0 arguments)
 .It Sx \&Ev Ta environmental variable (>0 arguments)
 .El

-.Ss Various semantic markup:
+.Ss Various semantic markup

 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&An Ta author name (>0 arguments)
 .It Sx \&Lk Ta hyperlink: Ar uri Op Ar name
 .Bl -column "Brq, Bro, Brc" description
 .It Sx \&An Ta author name (>0 arguments)
 .It Sx \&Lk Ta hyperlink: Ar uri Op Ar name


@@ -671,12 +674,10 @@ Examples:
 .Ss \&Ao
 Begin a block enclosed by angle brackets.
 Does not have any head arguments.
 .Ss \&Ao
 Begin a block enclosed by angle brackets.
 Does not have any head arguments.

-.Pp
-Examples:
-.Dl \&.Fl -key= \&Ns \&Ao \&Ar val \&Ac
-.Pp
-See also
-.Sx \&Aq .
+This macro is almost never useful.
+See
+.Sx \&Aq
+for more details.

 .Ss \&Ap
 Inserts an apostrophe without any surrounding whitespace.
 This is generally used as a grammatical device when referring to the verb
 .Ss \&Ap
 Inserts an apostrophe without any surrounding whitespace.
 This is generally used as a grammatical device when referring to the verb


@@ -686,19 +687,45 @@ Examples:
 .Dl \&.Fn execve \&Ap d
 .Ss \&Aq
 Encloses its arguments in angle brackets.
 .Dl \&.Fn execve \&Ap d
 .Ss \&Aq
 Encloses its arguments in angle brackets.

+The only important use case is for email addresses.
+See
+.Sx \&Mt
+for an example.

 .Pp
 .Pp

-Examples:
-.Dl \&.Fl -key= \&Ns \&Aq \&Ar val
+Occasionally, it is used for names of characters and keys, for example:
+.Bd -literal -offset indent
+Press the
+\&.Aq escape
+key to ...
+.Ed

 .Pp
 .Pp

-.Em Remarks :
-this macro is often abused for rendering URIs, which should instead use
+For URIs, use

 .Sx \&Lk
 .Sx \&Lk

+instead, and
+.Sx \&In
+for
+.Dq #include
+directives.
+Never wrap
+.Sx \&Ar
+in
+.Sx \&Aq .
+.Pp
+Since
+.Sx \&Aq
+usually renders with non-ASCII characters in non-ASCII output modes,
+do not use it where the ASCII characters
+.Sq <
+and
+.Sq >
+are required as syntax elements.
+Instead, use these characters directly in such cases, combining them
+with the macros
+.Sx \&Pf ,
+.Sx \&Ns ,

 or
 or

-.Sx \&Mt ,
-or to note pre-processor
-.Dq Li #include
-statements, which should use
-.Sx \&In .
+.Sx \&Eo
+as needed.

 .Pp
 See also
 .Sx \&Ao .
 .Pp
 See also
 .Sx \&Ao .


@@ -732,7 +759,7 @@ A version of
 .At .
 .It Cm III
 .At III .
 .At .
 .It Cm III
 .At III .

-.It Cm V[.[1-4]]?
+.It Cm V | V.[1-4]

 A version of
 .At V .
 .El
 A version of
 .At V .
 .El


@@ -969,10 +996,8 @@ argument.
 A columnated list.
 The
 .Fl width
 A columnated list.
 The
 .Fl width

-argument has no effect; instead, each argument specifies the width
-of one column, using either the scaling width syntax described in
-.Xr roff 7
-or the string length of the argument.
+argument has no effect; instead, the string length of each argument
+specifies the width of one column.

 If the first line of the body of a
 .Fl column
 list is not an
 If the first line of the body of a
 .Fl column
 list is not an


@@ -1209,7 +1234,7 @@ The
 .Ar month
 is the full English month name, the
 .Ar day
 .Ar month
 is the full English month name, the
 .Ar day

-is an optionally zero-padded numeral, and the
+is an integer number, and the

 .Ar year
 is the full four-digit year.
 .Pp
 .Ar year
 is the full four-digit year.
 .Pp


@@ -1239,8 +1264,8 @@ If no date string is given, the current date is used.
 .Pp
 Examples:
 .Dl \&.Dd $\&Mdocdate$
 .Pp
 Examples:
 .Dl \&.Dd $\&Mdocdate$

-.Dl \&.Dd $\&Mdocdate: July 21 2007$
-.Dl \&.Dd July 21, 2007
+.Dl \&.Dd $\&Mdocdate: July 2 2018$
+.Dl \&.Dd July 2, 2018

 .Pp
 See also
 .Sx \&Dt
 .Pp
 See also
 .Sx \&Dt


@@ -1622,7 +1647,7 @@ See also
 A function name.
 Its syntax is as follows:
 .Bd -ragged -offset indent
 A function name.
 Its syntax is as follows:
 .Bd -ragged -offset indent

-.Pf \. Ns Sx \&Fn
+.Pf . Sx \&Fn

 .Op Ar functype
 .Ar funcname
 .Op Oo Ar argtype Oc Ar argname
 .Op Ar functype
 .Ar funcname
 .Op Oo Ar argtype Oc Ar argname


@@ -1826,31 +1851,43 @@ The
 list is the most complicated.
 Its syntax is as follows:
 .Pp
 list is the most complicated.
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...

 .D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...
 .D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...

+.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...

 .Pp
 The arguments consist of one or more lines of text and macros
 representing a complete table line.
 .Pp
 The arguments consist of one or more lines of text and macros
 representing a complete table line.

-Cells within the line are delimited by tabs or by the special
+Cells within the line are delimited by the special

 .Sx \&Ta
 .Sx \&Ta

-block macro.
+block macro or by literal tab characters.
+.Pp
+Using literal tabs is strongly discouraged because they are very
+hard to use correctly and
+.Nm
+code using them is very hard to read.
+In particular, a blank character is syntactically significant
+before and after the literal tab character.
+If a word precedes or follows the tab without an intervening blank,
+that word is never interpreted as a macro call, but always output
+literally.
+.Pp

 The tab cell delimiter may only be used within the
 .Sx \&It
 line itself; on following lines, only the
 .Sx \&Ta
 The tab cell delimiter may only be used within the
 .Sx \&It
 line itself; on following lines, only the
 .Sx \&Ta

-macro can be used to delimit cells, and
+macro can be used to delimit cells, and portability requires that

 .Sx \&Ta
 .Sx \&Ta

-is only recognised as a macro when called by other macros,
-not as the first macro on a line.
+is called by other macros: some parsers do not recognize it when
+it appears as the first macro on a line.

 .Pp
 Note that quoted strings may span tab-delimited cells on an
 .Sx \&It
 line.
 For example,
 .Pp
 .Pp
 Note that quoted strings may span tab-delimited cells on an
 .Sx \&It
 line.
 For example,
 .Pp

-.Dl .It \(dqcol1 ; <TAB> col2 ;\(dq \&;
+.Dl .It \(dqcol1 ,\& <TAB> col2 ,\(dq \&;

 .Pp
 .Pp

-will preserve the semicolon whitespace except for the last.
+will preserve the whitespace before both commas,
+but not the whitespace before the semicolon.

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


@@ -1930,11 +1967,9 @@ Examples:
 .Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
 .Ss \&Nd
 A one line description of the manual's content.
 .Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
 .Ss \&Nd
 A one line description of the manual's content.

-This may only be invoked in the
-.Em SYNOPSIS
-section subsequent the
-.Sx \&Nm
-macro.
+This is the mandatory last macro of the
+.Em NAME
+section and not appropriate for other sections.

 .Pp
 Examples:
 .Dl Pf . Sx \&Nd mdoc language reference
 .Pp
 Examples:
 .Dl Pf . Sx \&Nd mdoc language reference


@@ -2095,7 +2130,7 @@ It is suggested to leave it unspecified, in which case
 .Xr mandoc 1
 uses its
 .Fl Ios
 .Xr mandoc 1
 uses its
 .Fl Ios

-argument, or, if that isn't specified either,
+argument or, if that isn't specified either,

 .Fa sysname
 and
 .Fa release
 .Fa sysname
 and
 .Fa release


@@ -2157,19 +2192,23 @@ See also
 Close parenthesised context opened by
 .Sx \&Po .
 .Ss \&Pf
 Close parenthesised context opened by
 .Sx \&Po .
 .Ss \&Pf

-Removes the space between its argument
-.Pq Dq prefix
-and the following macro.
+Removes the space between its argument and the following macro.

 Its syntax is as follows:
 .Pp
 .D1 .Pf Ar prefix macro arguments ...
 .Pp
 This is equivalent to:
 .Pp
 Its syntax is as follows:
 .Pp
 .D1 .Pf Ar prefix macro arguments ...
 .Pp
 This is equivalent to:
 .Pp

-.D1 .No Ar prefix No \&Ns Ar macro arguments ...
+.D1 .No \e& Ns Ar prefix No \&Ns Ar macro arguments ...
+.Pp
+The
+.Ar prefix
+argument is not parsed for macro names or delimiters,
+but used verbatim as if it were escaped.

 .Pp
 Examples:
 .Dl ".Pf $ Ar variable_name"
 .Pp
 Examples:
 .Dl ".Pf $ Ar variable_name"

+.Dl ".Pf . Ar macro_name"

 .Dl ".Pf 0x Ar hex_digits"
 .Pp
 See also
 .Dl ".Pf 0x Ar hex_digits"
 .Pp
 See also


@@ -2269,7 +2308,7 @@ Examples:
 \&.%A J. D. Ullman
 \&.%B Introduction to Automata Theory, Languages, and Computation
 \&.%I Addison-Wesley
 \&.%A J. D. Ullman
 \&.%B Introduction to Automata Theory, Languages, and Computation
 \&.%I Addison-Wesley

-\&.%C Reading, Massachusettes
+\&.%C Reading, Massachusetts

 \&.%D 1979
 \&.Re
 .Ed
 \&.%D 1979
 \&.Re
 .Ed


@@ -2560,11 +2599,6 @@ The second and last Technical Corrigendum.
 .br
 This standard is also called
 X/Open Portability Guide version 7.
 .br
 This standard is also called
 X/Open Portability Guide version 7.

-.Pp
-.It \-p1003.1-2013
-.St -p1003.1-2013
-.br
-This is the first Technical Corrigendum.

 .El
 .It Other standards
 .Pp
 .El
 .It Other standards
 .Pp


@@ -2707,42 +2741,18 @@ Link to another manual
 .Pq Qq cross-reference .
 Its syntax is as follows:
 .Pp
 .Pq Qq cross-reference .
 Its syntax is as follows:
 .Pp

-.D1 Pf \. Sx \&Xr Ar name Op section
+.D1 Pf \. Sx \&Xr Ar name section

 .Pp
 Cross reference the
 .Ar name
 and
 .Ar section
 .Pp
 Cross reference the
 .Ar name
 and
 .Ar section

-number of another man page;
-omitting the section number is rarely useful.
+number of another man page.

 .Pp
 Examples:
 .Dl \&.Xr mandoc 1
 .Dl \&.Xr mandoc 1 \&;
 .Dl \&.Xr mandoc 1 \&Ns s behaviour
 .Pp
 Examples:
 .Dl \&.Xr mandoc 1
 .Dl \&.Xr mandoc 1 \&;
 .Dl \&.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
-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 Ar height
-.Pp
-The
-.Ar height
-argument is a scaling width as described in
-.Xr roff 7 .
-If unspecified,
-.Sx \&sp
-asserts a single vertical space.

 .Sh MACRO SYNTAX
 The syntax of a macro depends on its classification.
 In this section,
 .Sh MACRO SYNTAX
 The syntax of a macro depends on its classification.
 In this section,


@@ -3026,9 +3036,7 @@ then the macro accepts an arbitrary number of arguments.
 .It Sx \&Ux  Ta    Yes      Ta    Yes      Ta    n
 .It Sx \&Va  Ta    Yes      Ta    Yes      Ta    n
 .It Sx \&Vt  Ta    Yes      Ta    Yes      Ta    >0
 .It Sx \&Ux  Ta    Yes      Ta    Yes      Ta    n
 .It Sx \&Va  Ta    Yes      Ta    Yes      Ta    n
 .It Sx \&Vt  Ta    Yes      Ta    Yes      Ta    >0

-.It Sx \&Xr  Ta    Yes      Ta    Yes      Ta    >0
-.It Sx \&br  Ta    \&No     Ta    \&No     Ta    0
-.It Sx \&sp  Ta    \&No     Ta    \&No     Ta    1
+.It Sx \&Xr  Ta    Yes      Ta    Yes      Ta    2

 .El
 .Ss Delimiters
 When a macro argument consists of one single input character
 .El
 .Ss Delimiters
 When a macro argument consists of one single input character


@@ -3046,6 +3054,8 @@ For many macros, when the leading arguments are opening delimiters,
 these delimiters are put before the macro scope,
 and when the trailing arguments are closing delimiters,
 these delimiters are put after the macro scope.
 these delimiters are put before the macro scope,
 and when the trailing arguments are closing delimiters,
 these delimiters are put after the macro scope.

+Spacing is suppressed after opening delimiters
+and before closing delimiters.

 For example,
 .Pp
 .D1 Pf \. \&Aq "( [ word ] ) ."
 For example,
 .Pp
 .D1 Pf \. \&Aq "( [ word ] ) ."


@@ -3102,7 +3112,7 @@ renders as:
 .D1 Fl a ( b | c \*(Ba d ) e
 .Pp
 This applies to both opening and closing delimiters,
 .D1 Fl a ( b | c \*(Ba d ) e
 .Pp
 This applies to both opening and closing delimiters,

-and also to the middle delimiter:
+and also to the middle delimiter, which does not suppress spacing:

 .Pp
 .Bl -tag -width Ds -offset indent -compact
 .It \&|
 .Pp
 .Bl -tag -width Ds -offset indent -compact
 .It \&|


@@ -3210,6 +3220,12 @@ but produces large indentations.
 .Xr mandoc_char 7 ,
 .Xr roff 7 ,
 .Xr tbl 7
 .Xr mandoc_char 7 ,
 .Xr roff 7 ,
 .Xr tbl 7

+.Pp
+The web page
+.Lk http://mandoc.bsd.lv/mdoc/ "extended documentation for the mdoc language"
+provides a few tutorial-style pages for beginners, an extensive style
+guide for advanced authors, and an alphabetic index helping to choose
+the best macros for various kinds of content.

 .Sh HISTORY
 The
 .Nm
 .Sh HISTORY
 The
 .Nm