-.\" $Id: mdoc.7,v 1.140 2010/07/19 21:59:48 kristaps Exp $
+.\" $Id: mdoc.7,v 1.159 2010/09/26 19:46:48 schwarze Exp $
.\"
.\" Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
.\" Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
.\" 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: September 26 2010 $
.Dt MDOC 7
.Os
.Sh NAME
.Bx
.Ux
manuals.
-In this reference document, we describe its syntax, structure, and
+This reference document describes its syntax, structure, and
usage.
-Our reference implementation is mandoc; the
+The reference implementation is
+.Xr mandoc 1 ;
+the
.Sx COMPATIBILITY
section describes compatibility with other troff \-mdoc implementations.
.Pp
A macro line with only a control character and comment escape,
.Sq \&.\e\*q ,
is also ignored.
-Macro lines with only a control character and optionally whitespace are
+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
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&
-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
.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.
.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
which encourages semantic annotation.
.Ss Predefined Strings
Historically,
-.Xr groff 1
+troff
also defined a set of package-specific
.Dq predefined strings ,
which, like
.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.
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.
-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
-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
-.Sq \&Em a :
+.Sq Op "Fl a" :
.Bd -literal -offset indent
-\&.Em "Em a"
+\&.Op "Fl a"
.Ed
.Pp
In free-form mode, quotes are regarded as opaque text.
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,
.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 \.
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
-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 )
\&.Sh NAME
\&.Nm foo
\&.Nd a description goes here
-\&.\e\*q The next is for sections 2, 3, & 9 only.
\&.\e\*q .Sh LIBRARY
+\&.\e\*q For sections 2, 3, & 9 only.
+\&.\e\*q Not used in OpenBSD.
\&.Sh SYNOPSIS
\&.Nm foo
\&.Op Fl options
\&.Nm
utility processes files ...
\&.\e\*q .Sh IMPLEMENTATION NOTES
-\&.\e\*q The next is for sections 2, 3, & 9 only.
+\&.\e\*q Not used in OpenBSD.
\&.\e\*q .Sh RETURN VALUES
-\&.\e\*q The next is for sections 1, 6, 7, & 8 only.
+\&.\e\*q For sections 2, 3, & 9 only.
\&.\e\*q .Sh ENVIRONMENT
+\&.\e\*q For sections 1, 6, 7, & 8 only.
\&.\e\*q .Sh FILES
-\&.\e\*q The next is for sections 1 & 8 only.
\&.\e\*q .Sh EXIT STATUS
+\&.\e\*q For sections 1, 6, & 8 only.
\&.\e\*q .Sh EXAMPLES
-\&.\e\*q The next is for sections 1, 4, 6, 7, & 8 only.
\&.\e\*q .Sh DIAGNOSTICS
-\&.\e\*q The next is for sections 2, 3, & 9 only.
+\&.\e\*q For sections 1, 4, 6, 7, & 8 only.
\&.\e\*q .Sh ERRORS
+\&.\e\*q For sections 2, 3, & 9 only.
\&.\e\*q .Sh SEE ALSO
\&.\e\*q .Xr foobar 1
\&.\e\*q .Sh STANDARDS
\&.\e\*q .Sh CAVEATS
\&.\e\*q .Sh BUGS
\&.\e\*q .Sh SECURITY CONSIDERATIONS
+\&.\e\*q Not used in OpenBSD.
.Ed
.Pp
-The sections in a
+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
-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
-\&.Nm name0
-\&.Nm name1
+\&.Nm name0 ,
+\&.Nm name1 ,
\&.Nm name2
-\&.Nd a short description
+\&.Nd a one line description
.Ed
.Pp
The
.Pp
For the second, function calls (sections 2, 3, 9):
.Bd -literal -offset indent
-\&.Vt extern const char *global;
\&.In header.h
+\&.Vt extern const char *global;
\&.Ft "char *"
\&.Fn foo "const char *src"
\&.Ft "char *"
and
.Sx \&Ft .
All of these macros are output on their own line.
-If two such dissimilar macros are pair-wise invoked (except for
+If two such dissimilar macros are pairwise invoked (except for
.Sx \&Ft
before
.Sx \&Fo
.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
-This expands upon the brief, one-line description in
+This expands upon the brief, one line description in
.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:
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
-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.
-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
-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.
.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.
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
-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
-Explanations of common misuses and misunderstandings should be explained
+Common misuses and misunderstandings should be explained
in this section.
.It Em BUGS
-Extant bugs should be described in this section.
+Known bugs, limitations, and work-arounds should be described
+in this section.
.It Em SECURITY CONSIDERATIONS
Documents any security precautions that operators should consider.
.El
.Sh MACRO SYNTAX
Macros are one to three three characters in length and begin with a
-control character ,
+control character,
.Sq \&. ,
at the beginning of the line.
An arbitrary amount of whitespace may sit between the control character
.Sq Fl \&Sh .
.Pp
The
-.Em Parsable
+.Em Parsed
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
\&.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
.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
\(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
\(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
\&.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
.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
-.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 \&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
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
.Sx \&Rs
block.
.Ss \&Ac
-Closes an
+Close an
.Sx \&Ao
block.
Does not have any tail arguments.
.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.
-This macro may alternatively accepts the following arguments, although
-these may not be specified along with a parameter:
+Requires either the name of an author or one of the following arguments:
.Pp
.Bl -tag -width "-nosplitX" -offset indent -compact
.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
+The default is
+.Fl nosplit .
+The effect of selecting either of the
+.Fl split
+modes ends at the beginning of the
+.Em AUTHORS
+section.
In the
.Em 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
+section, the default is
+.Fl nosplit
+for the first author listing and
.Fl split
-will cause the first listing also to be split.
-If not in the
-.Em AUTHORS
-section, the default is not to split.
+for all other author listings.
.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
-.Em AUTHORS
-section, so if one specifies
-.Sx \&An Fl nosplit
-in the general document body, it must be re-specified in the
-.Em AUTHORS
-section.
+.D1 \&.An Kristaps Dzonsons \&Aq kristaps@bsd.lv
.Ss \&Ao
-Begins a block enclosed by angled brackets.
+Begin a block enclosed by angle brackets.
Does not have any head arguments.
.Pp
Examples:
Examples:
.D1 \&.Fn execve \&Ap d
.Ss \&Aq
-Encloses its arguments in angled brackets.
+Encloses its arguments in angle brackets.
.Pp
Examples:
.D1 \&.Fl -key= \&Ns \&Aq \&Ar val
.Ss \&Ar
Command arguments.
If an argument is not provided, the string
-.Dq file ...
+.Dq file ...\&
is used as a default.
.Pp
Examples:
.D1 \&.Ar arg1 , arg2 .
.Ss \&At
Formats an AT&T version.
-Accepts at most one parameter:
+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]]?
-A system version of
-.At .
+A version of
+.At V .
.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
and
.Sx \&Ux .
.Ss \&Bc
-Closes a
+Close a
.Sx \&Bo
block.
Does not have any tail arguments.
.Ss \&Bd
-Begins a display block.
+Begin a display block.
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
-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
-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
-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
-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
-As one of the pre-defined strings
-.Ar indent ,
+One of the pre-defined strings
+.Cm indent ,
the width of standard indentation;
-.Ar indent-two ,
+.Cm indent-two ,
twice
-.Ar indent ;
-.Ar left ,
+.Cm indent ;
+.Cm left ,
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
-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
-.Ar 6n .
+.Sy 6n .
.It
-As a scaling unit following the syntax described in
+A width using the syntax described in
.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
-If not provided an argument, it will be ignored.
+When the argument is missing,
+.Fl offset
+is ignored.
.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
-\&.Bd \-unfilled \-offset two-indent \-compact
+\&.Bd \-literal \-offset indent \-compact
Hello world.
\&.Ed
.Ed
argument are equivalent, as are
.Fl symbolic
and
-.Cm \&Sy,
+.Cm \&Sy ,
and
.Fl literal
and
See also
.Sx \&Li ,
.Sx \&Ef ,
+.Sx \&Em ,
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
-Subsequent arguments are ignored.
The
.Fl words
-argument is required.
+argument is required; additional arguments are ignored.
.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
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
-.Fl type
+.Fl Ns Ar type
.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
-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 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
-argument varies the width of list bodies' left-margins.
+argument.
.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
-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
-.Sx \&It ,
-an
.Sx \&It
-context spanning each line is implied until an
+macro line,
.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
-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 ,
-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
-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 ,
-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
-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
-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
-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
-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.
+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
+.Sx \&El
+and
.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:
See also
.Sx \&Bo .
.Ss \&Brc
-Closes a
+Close a
.Sx \&Bro
block.
Does not have any tail arguments.
.Ss \&Bro
-Begins a block enclosed by curly braces.
+Begin a block enclosed by curly braces.
Does not have any head arguments.
.Pp
Examples:
.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.
and
.Sx \&Ux .
.Ss \&Cd
-Configuration declaration.
+Kernel configuration declaration.
This denotes strings accepted by
.Xr config 8 .
.Pp
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
+.Pp
+This macro is ignored by
+.Xr mandoc 1 .
.Ss \&Dc
-Closes a
+Close a
.Sx \&Do
block.
Does not have any tail arguments.
manual.
Its syntax is as follows:
.Pp
-.D1 Pf \. Sx \&Dd Cm date
+.D1 Pf \. Sx \&Dd Op Ar date
.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 .
-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 $\&Mdocdate$
and
.Sx \&D1 .
.Ss \&Do
-Begins a block enclosed by double quotes.
+Begin a block enclosed by double quotes.
Does not have any head arguments.
.Pp
Examples:
.Bd -ragged -offset indent
.Pf \. Sx \&Dt
.Oo
-.Cm title
+.Ar title
.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
-.It Cm title
+.It Ar title
The document's title (name), defaulting to
.Dq UNKNOWN
if unspecified.
It should be capitalised.
-.It Cm section
+.It Ar section
The manual section.
This may be one of
.Ar 1
It should correspond to the manual's filename suffix and defaults to
.Dq 1
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
or
.Ar CON
.Pq contributed manuals .
-.It Cm arch
+.It Ar arch
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.
.Sx \&Eo .
Its syntax is as follows:
.Pp
-.D1 Pf \. Sx \&Ec Op Cm TERM
+.D1 Pf \. Sx \&Ec Op Ar TERM
.Pp
The
-.Cm TERM
+.Ar TERM
argument is used as the enclosure tail, for example, specifying \e(rq
will emulate
.Sx \&Dc .
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
-Ends a keep context started by
+End a keep context started by
.Sx \&Bk .
.Ss \&El
-Ends a list context started by
+End a list context started by
.Sx \&Bl .
.Pp
See also
and
.Sx \&Li .
.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
-.D1 Pf \. Sx \&Eo Op Cm TERM
+.D1 Pf \. Sx \&Eo Op Ar TERM
.Pp
The
-.Cm TERM
+.Ar TERM
argument is used as the enclosure head, for example, specifying \e(lq
will emulate
.Sx \&Do .
.D1 \&.Ev DISPLAY
.D1 \&.Ev PATH
.Ss \&Ex
-Inserts text regarding a utility's exit value.
-This macro must consist of the
-.Fl std
-argument followed by 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
-is not provided, the document's name as stipulated in
+is not specified, the document's name set by
.Sx \&Nm
-is provided.
+is used.
.Pp
See also
.Sx \&Rv .
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.
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:
.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
section (only if invoked as the line macro), the first argument is
preceded by
.Dq #include ,
-the arguments is enclosed in angled braces.
+the arguments is enclosed in angle brackets.
.Pp
Examples:
.D1 \&.In sys/types
.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
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
and
.Sx \&Sm .
.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:
and
.Sx \&Ux .
.Ss \&Oc
-Closes multi-line
+Close multi-line
.Sx \&Oo
context.
.Ss \&Oo
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
.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:
and
.Sx \&Qo .
.Ss \&Re
-Closes a
+Close an
.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.
.D1 \&.Tn IBM
.Ss \&Ud
Prints out
-.Dq currently under development.
+.Dq currently under development .
.Ss \&Ux
Format the UNIX name.
Accepts no argument.
.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
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
-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
-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
-groff behaves inconsistently when encountering
-.Pf non- Sx \&Fa
-children of
.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
-groff behaves inconsistently when encountering
.Sx \&Ft
-and
-.Sx \&Fn
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.
-In mandoc, this is not the case.
See
.Sx \&Ft
and
.Sx \&Fn
-for the normalised behaviour.
+for the normalised behaviour in mandoc.
.It
-Historic groff does not break before an
-.Sx \&Fn
-when not invoked as the line macro in the
-.Em SYNOPSIS
-section.
-.It
-Historic groff formats the
.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
-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
-The comment syntax
-.Sq \e\."
-is no longer accepted.
+.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
+.Sx \&Lk
+only accepts a single link-name argument; the remainder is misformatted.
.It
-In groff, the
.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.
-mandoc does.
.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
-groff behaves irregularly when specifying
.Sq \ef
+.Pq font face
+and
+.Sq \ef
+.Pq font family face
.Sx Text Decoration
-within line-macro scopes.
-mandoc follows a consistent system.
+escapes behave irregularly when specified within line-macro scopes.
.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
-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
-Display offsets
.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 .
+.Fl offset Ar right .
+Groff does not implement centered and flush-right rendering either,
+but produces large indentations.
.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.
-.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 ,
+.Sq \ek
+.Pq horizontal position marker ,
+.Sq \eo
+.Pq text overstrike ,
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
-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 man 1 ,
.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-1.17.
+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
git.ckatri.com / mandoc.git / blobdiff