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Diff for /mandoc/mandoc.1 between version 1.57 and 1.148

version 1.57, 2010/04/08 07:40:03 version 1.148, 2015/02/06 08:28:35
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 .\"     $Id$  .\"     $Id$
 .\"  .\"
 .\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>  .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   .\" Copyright (c) 2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
 .\"  .\"
 .\" Permission to use, copy, modify, and distribute this software for any  .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above  .\" purpose with or without fee is hereby granted, provided that the above
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 .Dd $Mdocdate$  .Dd $Mdocdate$
 .Dt MANDOC 1  .Dt MANDOC 1
 .Os  .Os
 .  
 .  
 .Sh NAME  .Sh NAME
 .Nm mandoc  .Nm mandoc
 .Nd format and display UNIX manuals  .Nd format and display UNIX manuals
 .  
 .  
 .Sh SYNOPSIS  .Sh SYNOPSIS
 .Nm mandoc  .Nm mandoc
 .Op Fl f Ns Ar option...  .Op Fl acfhklV
   .Sm off
   .Op Fl I Cm os Li = Ar name
   .Sm on
   .Op Fl K Ns Ar encoding
 .Op Fl m Ns Ar format  .Op Fl m Ns Ar format
 .Op Fl O Ns Ar option...  .Op Fl O Ns Ar option
 .Op Fl T Ns Ar output  .Op Fl T Ns Ar output
 .Op Fl V  .Op Fl W Ns Ar level
 .Op Fl W Ns Ar err...  .Op Ar
 .Op Ar infile...  
 .  
 .  
 .Sh DESCRIPTION  .Sh DESCRIPTION
 The  The
 .Nm  .Nm
 utility formats  utility formats
 .Ux  .Ux
 manual pages for display.  manual pages for display.
 The arguments are as follows:  .Pp
 .  By default,
   .Nm
   reads
   .Xr mdoc 7
   or
   .Xr man 7
   text from stdin, implying
   .Fl m Ns Cm andoc ,
   and produces
   .Fl T Ns Cm locale
   output.
   .Pp
   The options are as follows:
 .Bl -tag -width Ds  .Bl -tag -width Ds
 .It Fl f Ns Ar option...  .It Fl a
 Comma-separated compiler options.  If the standard output is a terminal device and
 See  .Fl c
 .Sx Compiler Options  is not specified, use
 for details.  .Xr more 1
 .  to paginate the output, just like
   .Xr man 1
   would.
   .It Fl c
   Copy the formatted manual pages to the standard output without using
   .Xr more 1
   to paginate them.
   This is the default.
   It can be specified to override
   .Fl a .
   .It Fl f
   A synonym for
   .Xr whatis 1 .
   This overrides any earlier
   .Fl k
   and
   .Fl l
   options.
   .Sm off
   .It Fl I Cm os Li = Ar name
   .Sm on
   Override the default operating system
   .Ar name
   for the
   .Xr mdoc 7
   .Sq \&Os
   and for the
   .Xr man 7
   .Sq \&TH
   macro.
   .It Fl h
   Display only the SYNOPSIS lines.
   Implies
   .Fl c .
   .It Fl K Ns Ar encoding
   Specify the input encoding.
   The supported
   .Ar encoding
   arguments are
   .Cm us-ascii ,
   .Cm iso-8859-1 ,
   and
   .Cm utf-8 .
   If not specified, autodetection uses the first match:
   .Bl -tag -width iso-8859-1
   .It Cm utf-8
   if the first three bytes of the input file
   are the UTF-8 byte order mark (BOM, 0xefbbbf)
   .It Ar encoding
   if the first or second line of the input file matches the
   .Sy emacs
   mode line format
   .Pp
   .D1 .\e" -*- Oo ...; Oc coding: Ar encoding ; No -*-
   .It Cm utf-8
   if the first non-ASCII byte in the file introduces a valid UTF-8 sequence
   .It Cm iso-8859-1
   otherwise
   .El
   .It Fl k
   A synonym for
   .Xr apropos 1 .
   This overrides any earlier
   .Fl f
   and
   .Fl l
   options.
   .It Fl l
   A synonym for
   .Fl a .
   Also reverts any earlier
   .Fl f
   and
   .Fl k
   options.
 .It Fl m Ns Ar format  .It Fl m Ns Ar format
 Input format.  Input format.
 See  See
 .Sx Input Formats  .Sx Input Formats
 for available formats.  for available formats.
 Defaults to  Defaults to
 .Fl m Ns Ar andoc .  .Fl m Ns Cm andoc .
 .  .It Fl O Ns Ar option
 .It Fl O Ns Ar option...  
 Comma-separated output options.  Comma-separated output options.
 See  
 .Sx Output Options  
 for details.  
 .  
 .It Fl T Ns Ar output  .It Fl T Ns Ar output
 Output format.  Output format.
 See  See
 .Sx Output Formats  .Sx Output Formats
 for available formats.  for available formats.
 Defaults to  Defaults to
 .Fl T Ns Ar ascii .  .Fl T Ns Cm locale .
 .  
 .It Fl V  .It Fl V
 Print version and exit.  Print version and exit.
 .  .It Fl W Ns Ar level
 .It Fl W Ns Ar err...  Specify the minimum message
 Comma-separated warning options.  .Ar level
 Use  to be reported on the standard error output and to affect the exit status.
 .Fl W Ns Ar all  The
 to print warnings,  .Ar level
 .Fl W Ns Ar error  can be
 for warnings to be considered errors and cause utility  .Cm warning ,
 termination.  .Cm error ,
 Multiple  or
 .Fl W  .Cm unsupp ;
 arguments may be comma-separated, such as  .Cm all
 .Fl W Ns Ar error,all .  is an alias for
 .  .Cm warning .
 .It Ar infile...  By default,
 Read input from zero or more  .Nm
 .Ar infile .  is silent.
   See
   .Sx EXIT STATUS
   and
   .Sx DIAGNOSTICS
   for details.
   .Pp
   The special option
   .Fl W Ns Cm stop
   tells
   .Nm
   to exit after parsing a file that causes warnings or errors of at least
   the requested level.
   No formatted output will be produced from that file.
   If both a
   .Ar level
   and
   .Cm stop
   are requested, they can be joined with a comma, for example
   .Fl W Ns Cm error , Ns Cm stop .
   .It Ar file
   Read input from zero or more files.
 If unspecified, reads from stdin.  If unspecified, reads from stdin.
 If multiple files are specified,  If multiple files are specified,
 .Nm  .Nm
 will halt with the first failed parse.  will halt with the first failed parse.
 .El  .El
 .  
 .Pp  .Pp
 By default,  In
   .Fl f
   and
   .Fl k
   mode,
 .Nm  .Nm
 reads  also supports the options
 .Xr mdoc 7  .Fl CMmOSsw
 or  described in the
 .Xr man 7  .Xr apropos 1
 text from stdin, implying  manual.
 .Fl m Ns Ar andoc ,  
 and produces  
 .Fl T Ns Ar ascii  
 output.  
 .  
 .Pp  
 .Ex -std mandoc  
 .  
 .  
 .Ss Input Formats  .Ss Input Formats
 The  The
 .Nm  .Nm
Line 122  utility accepts
Line 215  utility accepts
 and  and
 .Xr man 7  .Xr man 7
 input with  input with
 .Fl m Ns Ar doc  .Fl m Ns Cm doc
 and  and
 .Fl m Ns Ar an ,  .Fl m Ns Cm an ,
 respectively.  respectively.
 The  The
 .Xr mdoc 7  .Xr mdoc 7
Line 133  format is
Line 226  format is
 recommended;  recommended;
 .Xr man 7  .Xr man 7
 should only be used for legacy manuals.  should only be used for legacy manuals.
 .  
 .Pp  .Pp
 A third option,  A third option,
 .Fl m Ns Ar andoc ,  .Fl m Ns Cm andoc ,
 which is also the default, determines encoding on-the-fly: if the first  which is also the default, determines encoding on-the-fly: if the first
 non-comment macro is  non-comment macro is
 .Sq \&Dd  .Sq \&Dd
Line 147  the
Line 239  the
 parser is used; otherwise, the  parser is used; otherwise, the
 .Xr man 7  .Xr man 7
 parser is used.  parser is used.
 .  
 .Pp  .Pp
 If multiple  If multiple
 files are specified with  files are specified with
 .Fl m Ns Ar andoc ,  .Fl m Ns Cm andoc ,
 each has its file-type determined this way.  each has its file-type determined this way.
 If multiple files are  If multiple files are
 specified and  specified and
 .Fl m Ns Ar doc  .Fl m Ns Cm doc
 or  or
 .Fl m Ns Ar an  .Fl m Ns Cm an
 is specified, then this format is used exclusively.  is specified, then this format is used exclusively.
 .  
 .  
 .Ss Output Formats  .Ss Output Formats
 The  The
 .Nm  .Nm
 utility accepts the following  utility accepts the following
 .Fl T  .Fl T
 arguments (see  arguments, which correspond to output modes:
 .Sx OUTPUT ) :  .Bl -tag -width "-Tlocale"
 .  .It Fl T Ns Cm ascii
 .Bl -tag -width Ds  Produce 7-bit ASCII output.
 .It Fl T Ns Ar ascii  
 Produce 7-bit ASCII output, backspace-encoded for bold and underline  
 styles.  
 This is the default.  
 See  See
 .Sx ASCII Output .  .Sx ASCII Output .
 .  .It Fl T Ns Cm html
 .It Fl T Ns Ar html  Produce HTML5, CSS1, and MathML output.
 Produce strict HTML-4.01 output, with a sane default style.  
 See  See
 .Sx HTML Output .  .Sx HTML Output .
 .  .It Fl T Ns Cm lint
 .It Fl T Ns Ar xhtml  
 Produce strict XHTML-1.0 output, with a sane default style.  
 See  
 .Sx XHTML Output .  
 .  
 .It Fl T Ns Ar tree  
 Produce an indented parse tree.  
 .  
 .It Fl T Ns Ar lint  
 Parse only: produce no output.  Parse only: produce no output.
 Implies  Implies
 .Fl W Ns Ar all  .Fl W Ns Cm warning .
 and  .It Fl T Ns Cm locale
 .Fl f Ns Ar strict .  Encode output using the current locale.
   This is the default.
   See
   .Sx Locale Output .
   .It Fl T Ns Cm man
   Produce
   .Xr man 7
   format output.
   See
   .Sx Man Output .
   .It Fl T Ns Cm pdf
   Produce PDF output.
   See
   .Sx PDF Output .
   .It Fl T Ns Cm ps
   Produce PostScript output.
   See
   .Sx PostScript Output .
   .It Fl T Ns Cm tree
   Produce an indented parse tree.
   .It Fl T Ns Cm utf8
   Encode output in the UTF\-8 multi-byte format.
   See
   .Sx UTF\-8 Output .
   .It Fl T Ns Cm xhtml
   This is a synonym for
   .Fl T Ns Cm html .
 .El  .El
 .  
 .Pp  .Pp
 If multiple input files are specified, these will be processed by the  If multiple input files are specified, these will be processed by the
 corresponding filter in-order.  corresponding filter in-order.
 .  .Ss ASCII Output
 .  Output produced by
 .Ss Compiler Options  .Fl T Ns Cm ascii
 Default compiler behaviour may be overridden with the  is rendered in standard 7-bit ASCII documented in
 .Fl f  .Xr ascii 7 .
 flag.  .Pp
 .  Font styles are applied by using back-spaced encoding such that an
   underlined character
   .Sq c
   is rendered as
   .Sq _ Ns \e[bs] Ns c ,
   where
   .Sq \e[bs]
   is the back-space character number 8.
   Emboldened characters are rendered as
   .Sq c Ns \e[bs] Ns c .
   .Pp
   The special characters documented in
   .Xr mandoc_char 7
   are rendered best-effort in an ASCII equivalent.
   .Pp
   Output width is limited to 78 visible columns unless literal input lines
   exceed this limit.
   .Pp
   The following
   .Fl O
   arguments are accepted:
 .Bl -tag -width Ds  .Bl -tag -width Ds
 .It Fl f Ns Ar ign-scope  .It Cm indent Ns = Ns Ar indent
 When rewinding the scope of a block macro, forces the compiler to ignore  The left margin for normal text is set to
 scope violations.  .Ar indent
 This can seriously mangle the resulting tree.  blank characters instead of the default of five for
 .Pq mdoc only  .Xr mdoc 7
 .  and seven for
 .It Fl f Ns Ar ign-escape  .Xr man 7 .
 Ignore invalid escape sequences.  Increasing this is not recommended; it may result in degraded formatting,
 This is the default, but the option can be used to override an earlier  for example overfull lines or ugly line breaks.
 .Fl f Ns Ar strict .  .It Cm width Ns = Ns Ar width
 .  The output width is set to
 .It Fl f Ns Ar no-ign-escape  .Ar width ,
 Don't ignore invalid escape sequences.  which will normalise to \(>=58.
 .  
 .It Fl f Ns Ar no-ign-macro  
 Do not ignore unknown macros at the start of input lines.  
 .  
 .It Fl f Ns Ar no-ign-chars  
 Do not ignore disallowed characters.  
 .  
 .It Fl f Ns Ar strict  
 Implies  
 .Fl f Ns Ar no-ign-escape ,  
 .Fl f Ns Ar no-ign-macro  
 and  
 .Fl f Ns Ar no-ign-chars .  
 .  
 .It Fl f Ns Ar ign-errors  
 When parsing multiple files, don't halt when one errors out.  
 Useful with  
 .Fl T Ns Ar lint  
 over a large set of manuals passed on the command line.  
 .El  .El
 .  .Ss HTML Output
 .  Output produced by
 .Ss Output Options  .Fl T Ns Cm html
 For the time being, only  conforms to HTML5 using optional self-closing tags.
 .Fl T Ns Ar html  Default styles use only CSS1.
 and  Equations rendered from
 .Fl T Ns Ar xhtml  .Xr eqn 7
 accepts output options:  blocks use MathML.
   .Pp
   The
   .Pa example.style.css
   file documents style-sheet classes available for customising output.
   If a style-sheet is not specified with
   .Fl O Ns Ar style ,
   .Fl T Ns Cm html
   defaults to simple output (via an embedded style-sheet)
   readable in any graphical or text-based web
   browser.
   .Pp
   Special characters are rendered in decimal-encoded UTF\-8.
   .Pp
   The following
   .Fl O
   arguments are accepted:
 .Bl -tag -width Ds  .Bl -tag -width Ds
 .It Fl O Ns Ar style=style.css  .It Cm fragment
 The file  Omit the <!DOCTYPE> declaration and the <html>, <head>, and <body>
 .Ar style.css  elements and only emit the subtree below the <body> element.
 is used for an external style-sheet.  The
 This must be a valid absolute or  .Cm style
 relative URI.  argument will be ignored.
 .It Fl O Ns Ar includes=fmt  This is useful when embedding manual content within existing documents.
   .It Cm includes Ns = Ns Ar fmt
 The string  The string
 .Ar fmt ,  .Ar fmt ,
 for example,  for example,
Line 270  Instances of
Line 388  Instances of
 are replaced with the include filename.  are replaced with the include filename.
 The default is not to present a  The default is not to present a
 hyperlink.  hyperlink.
 .It Fl O Ns Ar man=fmt  .It Cm man Ns = Ns Ar fmt
 The string  The string
 .Ar fmt ,  .Ar fmt ,
 for example,  for example,
Line 286  are replaced with the linked manual's name and section
Line 404  are replaced with the linked manual's name and section
 If no section is included, section 1 is assumed.  If no section is included, section 1 is assumed.
 The default is not to  The default is not to
 present a hyperlink.  present a hyperlink.
   .It Cm style Ns = Ns Ar style.css
   The file
   .Ar style.css
   is used for an external style-sheet.
   This must be a valid absolute or
   relative URI.
 .El  .El
 .  .Ss Locale Output
 .  Locale-depending output encoding is triggered with
 .Sh OUTPUT  .Fl T Ns Cm locale .
 This section documents output details of  This is the default.
 .Nm .  
 In general, output conforms to the traditional manual style of a header,  
 a body composed of sections and sub-sections, and a footer.  
 .Pp  .Pp
 The text style of output characters (non-macro characters, punctuation,  This option is not available on all systems: systems without locale
 and white-space) is dictated by context.  support, or those whose internal representation is not natively UCS-4,
   will fall back to
   .Fl T Ns Cm ascii .
   See
   .Sx ASCII Output
   for font style specification and available command-line arguments.
   .Ss Man Output
   Translate input format into
   .Xr man 7
   output format.
   This is useful for distributing manual sources to legacy systems
   lacking
   .Xr mdoc 7
   formatters.
 .Pp  .Pp
 White-space is generally stripped from input.  If
 This can be changed with  
 character escapes (specified in  
 .Xr mandoc_char 7 )  
 or literal modes (specified in  
 .Xr mdoc 7  .Xr mdoc 7
 and  is passed as input, it is translated into
 .Xr man 7 ) .  .Xr man 7 .
   If the input format is
   .Xr man 7 ,
   the input is copied to the output, expanding any
   .Xr roff 7
   .Sq so
   requests.
   The parser is also run, and as usual, the
   .Fl W
   level controls which
   .Sx DIAGNOSTICS
   are displayed before copying the input to the output.
   .Ss PDF Output
   PDF-1.1 output may be generated by
   .Fl T Ns Cm pdf .
   See
   .Sx PostScript Output
   for
   .Fl O
   arguments and defaults.
   .Ss PostScript Output
   PostScript
   .Qq Adobe-3.0
   Level-2 pages may be generated by
   .Fl T Ns Cm ps .
   Output pages default to letter sized and are rendered in the Times font
   family, 11-point.
   Margins are calculated as 1/9 the page length and width.
   Line-height is 1.4m.
 .Pp  .Pp
 If non-macro punctuation is set apart from words, such as in the phrase  Special characters are rendered as in
 .Dq to be \&, or not to be ,  .Sx ASCII Output .
 it's processed by  
 .Nm ,  
 regardless of output format, according to the following rules:  opening  
 punctuation  
 .Po  
 .Sq \&( ,  
 .Sq \&[ ,  
 and  
 .Sq \&{  
 .Pc  
 is not followed by a space; closing punctuation  
 .Po  
 .Sq \&. ,  
 .Sq \&, ,  
 .Sq \&; ,  
 .Sq \&: ,  
 .Sq \&? ,  
 .Sq \&! ,  
 .Sq \&) ,  
 .Sq \&]  
 and  
 .Sq \&}  
 .Pc  
 is not preceded by white-space.  
 .  
 .Pp  .Pp
 If the input is  The following
 .Xr mdoc 7 ,  .Fl O
 however, these rules are also applied to macro arguments when appropriate.  arguments are accepted:
 .  .Bl -tag -width Ds
 .  .It Cm paper Ns = Ns Ar name
 .Ss ASCII Output  The paper size
 Output produced by  .Ar name
 .Fl T Ns Ar ascii ,  may be one of
 which is the default, is rendered in standard 7-bit ASCII documented in  .Ar a3 ,
 .Xr ascii 7 .  .Ar a4 ,
 .Pp  .Ar a5 ,
 Font styles are applied by using back-spaced encoding such that an  .Ar legal ,
 underlined character  or
 .Sq c  .Ar letter .
 is rendered as  You may also manually specify dimensions as
 .Sq _ Ns \e[bs] Ns c ,  .Ar NNxNN ,
 where  width by height in millimetres.
 .Sq \e[bs]  If an unknown value is encountered,
 is the back-space character number 8.  .Ar letter
 Emboldened characters are rendered as  is used.
 .Sq c Ns \e[bs] Ns c .  .El
 .Pp  .Ss UTF\-8 Output
 The special characters documented in  Use
 .Xr mandoc_char 7  .Fl T Ns Cm utf8
 are rendered best-effort in an ASCII equivalent.  to force a UTF\-8 locale.
 .Pp  See
 Output width is limited to 78 visible columns unless literal input lines  .Sx Locale Output
 exceed this limit.  for details and options.
 .  .Sh ENVIRONMENT
 .  .Bl -tag -width MANPAGER
 .Ss HTML Output  .It Ev MANPAGER
 Output produced by  Any non-empty value of the environment variable
 .Fl T Ns Ar html  .Ev MANPAGER
 conforms to HTML-4.01 strict.  will be used instead of the standard pagination program,
 .Pp  .Xr more 1 .
 Font styles and page structure are applied using CSS2.  .It Ev PAGER
 By default, no font style is applied to any text,  Specifies the pagination program to use when
 although CSS2 is hard-coded to format  .Ev MANPAGER
 the basic structure of output.  is not defined.
 .Pp  If neither PAGER nor MANPAGER is defined,
   .Pa /usr/bin/more Fl s
   will be used.
   .El
   .Sh EXIT STATUS
 The  The
 .Pa example.style.css  .Nm
 file documents the range of styles applied to output and, if used, will  utility exits with one of the following values, controlled by the message
 cause rendered documents to appear as they do in  .Ar level
 .Fl T Ns Ar ascii .  associated with the
   .Fl W
   option:
 .Pp  .Pp
 Special characters are rendered in decimal-encoded UTF-8.  .Bl -tag -width Ds -compact
 .  .It 0
 .  No warnings or errors occurred, or those that did were ignored because
 .Ss XHTML Output  they were lower than the requested
 Output produced by  .Ar level .
 .Fl T Ns Ar xhtml  .It 2
 conforms to XHTML-1.0 strict.  At least one warning occurred, but no error, and
   .Fl W Ns Cm warning
   was specified.
   .It 3
   At least one parsing error occurred,
   but no unsupported feature was encountered, and
   .Fl W Ns Cm error
   or
   .Fl W Ns Cm warning
   was specified.
   .It 4
   At least one unsupported feature was encountered, and
   .Fl W Ns Cm unsupp ,
   .Fl W Ns Cm error
   or
   .Fl W Ns Cm warning
   was specified.
   .It 5
   Invalid command line arguments were specified.
   No input files have been read.
   .It 6
   An operating system error occurred, for example exhaustion
   of memory, file descriptors, or process table entries.
   Such errors cause
   .Nm
   to exit at once, possibly in the middle of parsing or formatting a file.
   .El
 .Pp  .Pp
 See  Note that selecting
 .Sx HTML Output  .Fl T Ns Cm lint
 for details; beyond generating XHTML tags instead of HTML tags, these  output mode implies
 output modes are identical.  .Fl W Ns Cm warning .
 .  
 .  
 .Sh EXAMPLES  .Sh EXAMPLES
 To page manuals to the terminal:  To page manuals to the terminal:
 .  
 .Pp  .Pp
 .D1 % mandoc \-Wall,error \-fstrict mandoc.1 2\*(Gt&1 | less  .Dl $ mandoc \-Wall,stop mandoc.1 2\*(Gt&1 | less
 .D1 % mandoc mandoc.1 mdoc.3 mdoc.7 | less  .Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
 .  
 .Pp  .Pp
 To produce HTML manuals with  To produce HTML manuals with
 .Ar style.css  .Ar style.css
 as the style-sheet:  as the style-sheet:
 .Pp  .Pp
 .D1 % mandoc \-Thtml -Ostyle=style.css mdoc.7 \*(Gt mdoc.7.html  .Dl $ mandoc \-Thtml -Ostyle=style.css mdoc.7 \*(Gt mdoc.7.html
 .Pp  .Pp
 To check over a large set of manuals:  To check over a large set of manuals:
 .  
 .Pp  .Pp
 .Dl % mandoc \-Tlint \-fign-errors `find /usr/src -name \e*\e.[1-9]`  .Dl $ mandoc \-Tlint `find /usr/src -name \e*\e.[1-9]`
 .  .Pp
 .  To produce a series of PostScript manuals for A4 paper:
 .Sh COMPATIBILITY  .Pp
 This section summarises  .Dl $ mandoc \-Tps \-Opaper=a4 mdoc.7 man.7 \*(Gt manuals.ps
   .Pp
   Convert a modern
   .Xr mdoc 7
   manual to the older
   .Xr man 7
   format, for use on systems lacking an
   .Xr mdoc 7
   parser:
   .Pp
   .Dl $ mandoc \-Tman foo.mdoc \*(Gt foo.man
   .Sh DIAGNOSTICS
   Messages displayed by
 .Nm  .Nm
 compatibility with  follow this format:
 .Xr groff 1 .  .Pp
 Each input and output format is separately noted.  .D1 Nm Ns : Ar file : Ns Ar line : Ns Ar column : level : message : macro args
 .  .Pp
 .  Line and column numbers start at 1.
 .Ss ASCII Compatibility  Both are omitted for messages referring to an input file as a whole.
 .Bl -bullet -compact  Macro names and arguments are omitted where meaningless.
 .It  Fatal messages about invalid command line arguments
   or operating system errors, for example when memory is exhausted,
   may also omit the
   .Ar file
   and
   .Ar level
   fields.
   .Pp
   Message levels have the following meanings:
   .Bl -tag -width "warning"
   .It Cm unsupp
   An input file uses unsupported low-level
   .Xr roff 7
   features.
   The output may be incomplete and/or misformatted,
   so using GNU troff instead of
   .Nm
   to process the file may be preferable.
   .It Cm error
   An input file contains invalid syntax that cannot be safely interpreted.
   By discarding part of the input or inserting missing tokens,
   the parser is able to continue, and the error does not prevent
   generation of formatted output, but typically, preparing that
   output involves information loss, broken document structure
   or unintended formatting, no matter whether
   .Nm
   or GNU troff is used.
   In many cases, the output of
   .Nm
   and GNU troff is identical, but in some,
   .Nm
   is more resilient than GNU troff with respect to malformed input.
   .Pp
   Non-existent or unreadable input files are also reported on the
   .Cm error
   level.
   In that case, the parser cannot even be started and no output
   is produced from those input files.
   .It Cm warning
   An input file uses obsolete, discouraged or non-portable syntax.
   All the same, the meaning of the input is unambiguous and a correct
   rendering can be produced.
   Documents causing warnings may render poorly when using other
   formatting tools instead of
   .Nm .
   .El
   .Pp
   Messages of the
   .Cm warning ,
   .Cm error ,
   and
   .Cm unsupp
   levels except those about non-existent or unreadable input files
   are hidden unless their level, or a lower level, is requested using a
   .Fl W
   option or
   .Fl T Ns Cm lint
   output mode.
   .Ss Warnings related to the document prologue
   .Bl -ohang
   .It Sy "missing manual title, using UNTITLED"
   .Pq mdoc
   A
   .Ic \&Dt
   macro has no arguments, or there is no
   .Ic \&Dt
   macro before the first non-prologue macro.
   .It Sy "missing manual title, using \(dq\(dq"
   .Pq man
   There is no
   .Ic \&TH
   macro, or it has no arguments.
   .It Sy "lower case character in document title"
   .Pq mdoc , man
   The title is still used as given in the
   .Ic \&Dt
   or
   .Ic \&TH
   macro.
   .It Sy "missing manual section, using \(dq\(dq"
   .Pq mdoc , man
   A
   .Ic \&Dt
   or
   .Ic \&TH
   macro lacks the mandatory section argument.
   .It Sy "unknown manual section"
   .Pq mdoc
   The section number in a
   .Ic \&Dt
   line is invalid, but still used.
   .It Sy "missing date, using today's date"
   .Pq mdoc, man
   The document was parsed as
   .Xr mdoc 7
   and it has no
   .Ic \&Dd
   macro, or the
   .Ic \&Dd
   macro has no arguments or only empty arguments;
   or the document was parsed as
   .Xr man 7
   and it has no
   .Ic \&TH
   macro, or the
   .Ic \&TH
   macro has less than three arguments or its third argument is empty.
   .It Sy "cannot parse date, using it verbatim"
   .Pq mdoc , man
   The date given in a
   .Ic \&Dd
   or
   .Ic \&TH
   macro does not follow the conventional format.
   .It Sy "missing Os macro, using \(dq\(dq"
   .Pq mdoc
   The default or current system is not shown in this case.
   .It Sy "duplicate prologue macro"
   .Pq mdoc
   One of the prologue macros occurs more than once.
   The last instance overrides all previous ones.
   .It Sy "late prologue macro"
   .Pq mdoc
   A
   .Ic \&Dd
   or
   .Ic \&Os
   macro occurs after some non-prologue macro, but still takes effect.
   .It Sy "skipping late title macro"
   .Pq mdoc
 The  The
 .Sq \e~  .Ic \&Dt
 special character doesn't produce expected behaviour in  macro can only occur before the first non-prologue macro
 .Fl T Ns Ar ascii .  because traditional formatters write the page header
 .  before parsing the document body.
 .It  Even though this technical restriction does not apply to
 The  .Nm ,
 .Sq \&Bd \-literal  traditional semantics is preserved.
   The late macro is discarded including its arguments.
   .It Sy "prologue macros out of order"
   .Pq mdoc
   The prologue macros are not given in the conventional order
   .Ic \&Dd ,
   .Ic \&Dt ,
   .Ic \&Os .
   All three macros are used even when given in another order.
   .El
   .Ss Warnings regarding document structure
   .Bl -ohang
   .It Sy ".so is fragile, better use ln(1)"
   .Pq roff
   Including files only works when the parser program runs with the correct
   current working directory.
   .It Sy "no document body"
   .Pq mdoc , man
   The document body contains neither text nor macros.
   An empty document is shown, consisting only of a header and a footer line.
   .It Sy "content before first section header"
   .Pq mdoc , man
   Some macros or text precede the first
   .Ic \&Sh
   or
   .Ic \&SH
   section header.
   The offending macros and text are parsed and added to the top level
   of the syntax tree, outside any section block.
   .It Sy "first section is not NAME"
   .Pq mdoc
   The argument of the first
   .Ic \&Sh
   macro is not
   .Sq NAME .
   This may confuse
   .Xr makewhatis 8
 and  and
 .Sq \&Bd \-unfilled  .Xr apropos 1 .
 macros of  .It Sy "bad NAME section contents"
   .Pq mdoc
   The last node in the NAME section is not an
   .Ic \&Nd
   macro, or any preceding macro is not
   .Ic \&Nm ,
   or the NAME section is completely empty.
   This may confuse
   .Xr makewhatis 8
   and
   .Xr apropos 1 .
   .It Sy "missing description line, using \(dq\(dq"
   .Pq mdoc
   The
   .Ic \&Nd
   macro lacks the required argument.
   The title line of the manual will end after the dash.
   .It Sy "sections out of conventional order"
   .Pq mdoc
   A standard section occurs after another section it usually precedes.
   All section titles are used as given,
   and the order of sections is not changed.
   .It Sy "duplicate section title"
   .Pq mdoc
   The same standard section title occurs more than once.
   .It Sy "unexpected section"
   .Pq mdoc
   A standard section header occurs in a section of the manual
   where it normally isn't useful.
   .It Sy "unusual Xr order"
   .Pq mdoc
   In the SEE ALSO section, an
   .Ic \&Xr
   macro with a lower section number follows one with a higher number,
   or two
   .Ic \&Xr
   macros refering to the same section are out of alphabetical order.
   .It Sy "unusual Xr punctuation"
   .Pq mdoc
   In the SEE ALSO section, punctuation between two
   .Ic \&Xr
   macros differs from a single comma, or there is trailing punctuation
   after the last
   .Ic \&Xr
   macro.
   .It Sy "AUTHORS section without An macro"
   .Pq mdoc
   An AUTHORS sections contains no
   .Ic \&An
   macros, or only empty ones.
   Probably, there are author names lacking markup.
   .El
   .Ss "Warnings related to macros and nesting"
   .Bl -ohang
   .It Sy "obsolete macro"
   .Pq mdoc
   See the
 .Xr mdoc 7  .Xr mdoc 7
 in  manual for replacements.
 .Fl T Ns Ar ascii  .It Sy "macro neither callable nor escaped"
 are synonyms, as are \-filled and \-ragged.  .Pq mdoc
 .  The name of a macro that is not callable appears on a macro line.
 .It  It is printed verbatim.
   If the intention is to call it, move it to its own line;
   otherwise, escape it by prepending
   .Sq \e& .
   .It Sy "skipping paragraph macro"
 In  In
 .Xr groff 1 ,  
 the  
 .Sq \&Pa  
 .Xr mdoc 7  .Xr mdoc 7
 macro does not underline when scoped under an  documents, this happens
 .Sq \&It  .Bl -dash -compact
 in the FILES section.  
 This behaves correctly in  
 .Nm .  
 .  
 .It  .It
 A list or display following  at the beginning and end of sections and subsections
 .Sq \&Ss  
 .Xr mdoc 7  
 macro in  
 .Fl T Ns Ar ascii  
 does not assert a prior vertical break, just as it doesn't with  
 .Sq \&Sh .  
 .  
 .It  .It
 The  right before non-compact lists and displays
 .Sq \&na  .It
   at the end of items in non-column, non-compact lists
   .It
   and for multiple consecutive paragraph macros.
   .El
   In
 .Xr man 7  .Xr man 7
 macro in  documents, it happens
 .Fl T Ns Ar ascii  .Bl -dash -compact
 has no effect.  
 .  
 .It  .It
 Words aren't hyphenated.  for empty
 .  .Ic \&P ,
   .Ic \&PP ,
   and
   .Ic \&LP
   macros
 .It  .It
 In normal mode (not a literal block), blocks of spaces aren't preserved,  for
 so double spaces following sentence closure are reduced to a single space;  .Ic \&IP
 .Xr groff 1  macros having neither head nor body arguments
 retains spaces.  
 .  
 .It  .It
 Sentences are unilaterally monospaced.  for
   .Ic \&br
   or
   .Ic \&sp
   right after
   .Ic \&SH
   or
   .Ic \&SS
 .El  .El
 .  .It Sy "moving paragraph macro out of list"
 .  .Pq mdoc
 .Ss HTML/XHTML Compatibility  A list item in a
 .Bl -bullet -compact  .Ic \&Bl
   list contains a trailing paragraph macro.
   The paragraph macro is moved after the end of the list.
   .It Sy "skipping no-space macro"
   .Pq mdoc
   An input line begins with an
   .Ic \&Ns
   macro.
   The macro is ignored.
   .It Sy "blocks badly nested"
   .Pq mdoc
   If two blocks intersect, one should completely contain the other.
   Otherwise, rendered output is likely to look strange in any output
   format, and rendering in SGML-based output formats is likely to be
   outright wrong because such languages do not support badly nested
   blocks at all.
   Typical examples of badly nested blocks are
   .Qq Ic \&Ao \&Bo \&Ac \&Bc
   and
   .Qq Ic \&Ao \&Bq \&Ac .
   In these examples,
   .Ic \&Ac
   breaks
   .Ic \&Bo
   and
   .Ic \&Bq ,
   respectively.
   .It Sy "nested displays are not portable"
   .Pq mdoc
   A
   .Ic \&Bd ,
   .Ic \&D1 ,
   or
   .Ic \&Dl
   display occurs nested inside another
   .Ic \&Bd
   display.
   This works with
   .Nm ,
   but fails with most other implementations.
   .It Sy "moving content out of list"
   .Pq mdoc
   A
   .Ic \&Bl
   list block contains text or macros before the first
   .Ic \&It
   macro.
   The offending children are moved before the beginning of the list.
   .It Sy ".Vt block has child macro"
   .Pq mdoc
   The
   .Ic \&Vt
   macro supports plain text arguments only.
   Formatting may be ugly and semantic searching
   for the affected content might not work.
   .It Sy "fill mode already enabled, skipping"
   .Pq man
   A
   .Ic \&fi
   request occurs even though the document is still in fill mode,
   or already switched back to fill mode.
   It has no effect.
   .It Sy "fill mode already disabled, skipping"
   .Pq man
   An
   .Ic \&nf
   request occurs even though the document already switched to no-fill mode
   and did not switch back to fill mode yet.
   It has no effect.
   .It Sy "line scope broken"
   .Pq man
   While parsing the next-line scope of the previous macro,
   another macro is found that prematurely terminates the previous one.
   The previous, interrupted macro is deleted from the parse tree.
   .El
   .Ss "Warnings related to missing arguments"
   .Bl -ohang
   .It Sy "skipping empty request"
   .Pq roff , eqn
   The macro name is missing from a macro definition request,
   or an
   .Xr eqn 7
   control statement or operation keyword lacks its required argument.
   .It Sy "conditional request controls empty scope"
   .Pq roff
   A conditional request is only useful if any of the following
   follows it on the same logical input line:
   .Bl -dash -compact
 .It  .It
 The  The
 .Sq \efP  .Sq \e{
 escape will revert the font to the previous  keyword to open a multi-line scope.
 .Sq \ef  
 escape, not to the last rendered decoration, which is now dictated by  
 CSS instead of hard-coded.  
 It also will not span past the current scope,  
 for the same reason.  
 Note that in  
 .Sx ASCII Output  
 mode, this will work fine.  
 .It  .It
   A request or macro or some text, resulting in a single-line scope.
   .It
   The immediate end of the logical line without any intervening whitespace,
   resulting in next-line scope.
   .El
   Here, a conditional request is followed by trailing whitespace only,
   and there is no other content on its logical input line.
   Note that it doesn't matter whether the logical input line is split
   across multiple physical input lines using
   .Sq \e
   line continuation characters.
   This is one of the rare cases
   where trailing whitespace is syntactically significant.
   The conditional request controls a scope containing whitespace only,
   so it is unlikely to have a significant effect,
   except that it may control a following
   .Ic \&el
   clause.
   .It Sy "skipping empty macro"
   .Pq mdoc
   The indicated macro has no arguments and hence no effect.
   .It Sy "empty block"
   .Pq mdoc , man
   A
   .Ic \&Bd ,
   .Ic \&Bk ,
   .Ic \&Bl ,
   .Ic \&D1 ,
   .Ic \&Dl ,
   .Ic \&RS ,
   or
   .Ic \&UR
   block contains nothing in its body and will produce no output.
   .It Sy "empty argument, using 0n"
   .Pq mdoc
   The required width is missing after
   .Ic \&Bd
   or
   .Ic \&Bl
   .Fl offset
   or
   .Fl width.
   .It Sy "missing display type, using -ragged"
   .Pq mdoc
 The  The
   .Ic \&Bd
   macro is invoked without the required display type.
   .It Sy "list type is not the first argument"
   .Pq mdoc
   In a
   .Ic \&Bl
   macro, at least one other argument precedes the type argument.
   The
   .Nm
   utility copes with any argument order, but some other
 .Xr mdoc 7  .Xr mdoc 7
 .Sq \&Bl \-hang  implementations do not.
   .It Sy "missing -width in -tag list, using 8n"
   .Pq mdoc
   Every
   .Ic \&Bl
   macro having the
   .Fl tag
   argument requires
   .Fl width ,
   too.
   .It Sy "missing utility name, using \(dq\(dq"
   .Pq mdoc
   The
   .Ic \&Ex Fl std
   macro is called without an argument before
   .Ic \&Nm
   has first been called with an argument.
   .It Sy "missing function name, using \(dq\(dq"
   .Pq mdoc
   The
   .Ic \&Fo
   macro is called without an argument.
   No function name is printed.
   .It Sy "empty head in list item"
   .Pq mdoc
   In a
   .Ic \&Bl
   .Fl diag ,
   .Fl hang ,
   .Fl inset ,
   .Fl ohang ,
   or
   .Fl tag
   list, an
   .Ic \&It
   macro lacks the required argument.
   The item head is left empty.
   .It Sy "empty list item"
   .Pq mdoc
   In a
   .Ic \&Bl
   .Fl bullet ,
   .Fl dash ,
   .Fl enum ,
   or
   .Fl hyphen
   list, an
   .Ic \&It
   block is empty.
   An empty list item is shown.
   .It Sy "missing font type"
   .Pq mdoc
   A
   .Ic \&Bf
   macro has no argument.
   It switches to the default font,
   .Cm \efR .
   .It Sy "unknown font type"
   .Pq mdoc
   The
   .Ic \&Bf
   argument is invalid.
   The default font
   .Cm \efR
   is used instead.
   .It Sy "nothing follows prefix"
   .Pq mdoc
   A
   .Ic \&Pf
   macro has no argument, or only one argument and no macro follows
   on the same input line.
   This defeats its purpose; in particular, spacing is not suppressed
   before the text or macros following on the next input line.
   .It Sy "empty reference block"
   .Pq mdoc
   An
   .Ic \&Rs
   macro is immediately followed by an
   .Ic \&Re
   macro on the next input line.
   Such an empty block does not produce any output.
   .It Sy "missing -std argument, adding it"
   .Pq mdoc
   An
   .Ic \&Ex
   or
   .Ic \&Rv
   macro lacks the required
   .Fl std
   argument.
   The
   .Nm
   utility assumes
   .Fl std
   even when it is not specified, but other implementations may not.
   .It Sy "missing eqn box, using \(dq\(dq"
   .Pq eqn
   A diacritic mark or a binary operator is found,
   but there is nothing to the left of it.
   An empty box is inserted.
   .El
   .Ss "Warnings related to bad macro arguments"
   .Bl -ohang
   .It Sy "unterminated quoted argument"
   .Pq roff
   Macro arguments can be enclosed in double quote characters
   such that space characters and macro names contained in the quoted
   argument need not be escaped.
   The closing quote of the last argument of a macro can be omitted.
   However, omitting it is not recommended because it makes the code
   harder to read.
   .It Sy "duplicate argument"
   .Pq mdoc
   A
   .Ic \&Bd
   or
   .Ic \&Bl
   macro has more than one
   .Fl compact ,
   more than one
   .Fl offset ,
   or more than one
   .Fl width
   argument.
   All but the last instances of these arguments are ignored.
   .It Sy "skipping duplicate argument"
   .Pq mdoc
   An
   .Ic \&An
   macro has more than one
   .Fl split
   or
   .Fl nosplit
   argument.
   All but the first of these arguments are ignored.
   .It Sy "skipping duplicate display type"
   .Pq mdoc
   A
   .Ic \&Bd
   macro has more than one type argument; the first one is used.
   .It Sy "skipping duplicate list type"
   .Pq mdoc
   A
   .Ic \&Bl
   macro has more than one type argument; the first one is used.
   .It Sy "skipping -width argument"
   .Pq mdoc
   A
   .Ic \&Bl
   .Fl column ,
   .Fl diag ,
   .Fl ohang ,
   .Fl inset ,
   or
   .Fl item
   list has a
   .Fl width
   argument.
   That has no effect.
   .It Sy "unknown AT&T UNIX version"
   .Pq mdoc
   An
   .Ic \&At
   macro has an invalid argument.
   It is used verbatim, with
   .Qq "AT&T UNIX "
   prefixed to it.
   .It Sy "comma in function argument"
   .Pq mdoc
   An argument of an
   .Ic \&Fa
   or
   .Ic \&Fn
   macro contains a comma; it should probably be split into two arguments.
   .It Sy "parenthesis in function name"
   .Pq mdoc
   The first argument of an
   .Ic \&Fc
   or
   .Ic \&Fn
   macro contains an opening or closing parenthesis; that's probably wrong,
   parentheses are added automatically.
   .It Sy "invalid content in Rs block"
   .Pq mdoc
   An
   .Ic \&Rs
   block contains plain text or non-% macros.
   The bogus content is left in the syntax tree.
   Formatting may be poor.
   .It Sy "invalid Boolean argument"
   .Pq mdoc
   An
   .Ic \&Sm
   macro has an argument other than
   .Cm on
   or
   .Cm off .
   The invalid argument is moved out of the macro, which leaves the macro
   empty, causing it to toggle the spacing mode.
   .It Sy "unknown font, skipping request"
   .Pq man , tbl
   A
   .Xr roff 7
   .Ic \&ft
   request or a
   .Xr tbl 7
   .Ic \&f
   layout modifier has an unknown
   .Ar font
   argument.
   .El
   .Ss "Warnings related to plain text"
   .Bl -ohang
   .It Sy "blank line in fill mode, using .sp"
   .Pq mdoc
   The meaning of blank input lines is only well-defined in non-fill mode:
   In fill mode, line breaks of text input lines are not supposed to be
   significant.
   However, for compatibility with groff, blank lines in fill mode
   are replaced with
   .Ic \&sp
   requests.
   .It Sy "tab in filled text"
   .Pq mdoc , man
   The meaning of tab characters is only well-defined in non-fill mode:
   In fill mode, whitespace is not supposed to be significant
   on text input lines.
   As an implementation dependent choice, tab characters on text lines
   are passed through to the formatters in any case.
   Given that the text before the tab character will be filled,
   it is hard to predict which tab stop position the tab will advance to.
   .It Sy "whitespace at end of input line"
   .Pq mdoc , man , roff
   Whitespace at the end of input lines is almost never semantically
   significant \(em but in the odd case where it might be, it is
   extremely confusing when reviewing and maintaining documents.
   .It Sy "bad comment style"
   .Pq roff
   Comment lines start with a dot, a backslash, and a double-quote character.
   The
   .Nm
   utility treats the line as a comment line even without the backslash,
   but leaving out the backslash might not be portable.
   .It Sy "invalid escape sequence"
   .Pq roff
   An escape sequence has an invalid opening argument delimiter, lacks the
   closing argument delimiter, or the argument has too few characters.
   If the argument is incomplete,
   .Ic \e*
 and  and
 .Sq \&Bl \-tag  .Ic \en
 list types render similarly (no break following overreached left-hand  expand to an empty string,
 side) due to the expressive constraints of HTML.  .Ic \eB
 .  to the digit
   .Sq 0 ,
   and
   .Ic \ew
   to the length of the incomplete argument.
   All other invalid escape sequences are ignored.
   .It Sy "undefined string, using \(dq\(dq"
   .Pq roff
   If a string is used without being defined before,
   its value is implicitly set to the empty string.
   However, defining strings explicitly before use
   keeps the code more readable.
   .El
   .Ss "Warnings related to tables"
   .Bl -ohang
   .It Sy "tbl line starts with span"
   .Pq tbl
   The first cell in a table layout line is a horizontal span
   .Pq Sq Cm s .
   Data provided for this cell is ignored, and nothing is printed in the cell.
   .It Sy "tbl column starts with span"
   .Pq tbl
   The first line of a table layout specification
   requests a vertical span
   .Pq Sq Cm ^ .
   Data provided for this cell is ignored, and nothing is printed in the cell.
   .It Sy "skipping vertical bar in tbl layout"
   .Pq tbl
   A table layout specification contains more than two consecutive vertical bars.
   A double bar is printed, all additional bars are discarded.
   .El
   .Ss "Errors related to tables"
   .Bl -ohang
   .It Sy "non-alphabetic character in tbl options"
   .Pq tbl
   The table options line contains a character other than a letter,
   blank, or comma where the beginning of an option name is expected.
   The character is ignored.
   .It Sy "skipping unknown tbl option"
   .Pq tbl
   The table options line contains a string of letters that does not
   match any known option name.
   The word is ignored.
   .It Sy "missing tbl option argument"
   .Pq tbl
   A table option that requires an argument is not followed by an
   opening parenthesis, or the opening parenthesis is immediately
   followed by a closing parenthesis.
   The option is ignored.
   .It Sy "wrong tbl option argument size"
   .Pq tbl
   A table option argument contains an invalid number of characters.
   Both the option and the argument are ignored.
   .It Sy "empty tbl layout"
   .Pq tbl
   A table layout specification is completely empty,
   specifying zero lines and zero columns.
   As a fallback, a single left-justified column is used.
   .It Sy "invalid character in tbl layout"
   .Pq tbl
   A table layout specification contains a character that can neither
   be interpreted as a layout key character nor as a layout modifier,
   or a modifier precedes the first key.
   The invalid character is discarded.
   .It Sy "unmatched parenthesis in tbl layout"
   .Pq tbl
   A table layout specification contains an opening parenthesis,
   but no matching closing parenthesis.
   The rest of the input line, starting from the parenthesis, has no effect.
   .It Sy "tbl without any data cells"
   .Pq tbl
   A table does not contain any data cells.
   It will probably produce no output.
   .It Sy "ignoring data in spanned tbl cell"
   .Pq tbl
   A table cell is marked as a horizontal span
   .Pq Sq Cm s
   or vertical span
   .Pq Sq Cm ^
   in the table layout, but it contains data.
   The data is ignored.
   .It Sy "ignoring extra tbl data cells"
   .Pq tbl
   A data line contains more cells than the corresponding layout line.
   The data in the extra cells is ignored.
   .It Sy "data block open at end of tbl"
   .Pq tbl
   A data block is opened with
   .Cm T{ ,
   but never closed with a matching
   .Cm T} .
   The remaining data lines of the table are all put into one cell,
   and any remaining cells stay empty.
   .El
   .Ss "Errors related to roff, mdoc, and man code"
   .Bl -ohang
   .It Sy "input stack limit exceeded, infinite loop?"
   .Pq roff
   Explicit recursion limits are implemented for the following features,
   in order to prevent infinite loops:
   .Bl -dash -compact
 .It  .It
   expansion of nested escape sequences
   including expansion of strings and number registers,
   .It
   expansion of nested user-defined macros,
   .It
   and
   .Ic \&so
   file inclusion.
   .El
   When a limit is hit, the output is incorrect, typically losing
   some content, but the parser can continue.
   .It Sy "skipping bad character"
   .Pq mdoc , man , roff
   The input file contains a byte that is not a printable
   .Xr ascii 7
   character.
   The message mentions the character number.
   The offending byte is replaced with a question mark
   .Pq Sq \&? .
   Consider editing the input file to replace the byte with an ASCII
   transliteration of the intended character.
   .It Sy "skipping unknown macro"
   .Pq mdoc , man , roff
   The first identifier on a request or macro line is neither recognized as a
   .Xr roff 7
   request, nor as a user-defined macro, nor, respectively, as an
   .Xr mdoc 7
   or
   .Xr man 7
   macro.
   It may be mistyped or unsupported.
   The request or macro is discarded including its arguments.
   .It Sy "skipping insecure request"
   .Pq roff
   An input file attempted to run a shell command
   or to read or write an external file.
   Such attempts are denied for security reasons.
   .It Sy "skipping item outside list"
   .Pq mdoc , eqn
   An
   .Ic \&It
   macro occurs outside any
   .Ic \&Bl
   list, or an
   .Xr eqn 7
   .Ic above
   delimiter occurs outside any pile.
   It is discarded including its arguments.
   .It Sy "skipping column outside column list"
   .Pq mdoc
   A
   .Ic \&Ta
   macro occurs outside any
   .Ic \&Bl Fl column
   block.
   It is discarded including its arguments.
   .It Sy "skipping end of block that is not open"
   .Pq mdoc , man , eqn , tbl , roff
   Various syntax elements can only be used to explicitly close blocks
   that have previously been opened.
   An
   .Xr mdoc 7
   block closing macro, a
   .Xr man 7
   .Ic \&RE
   or
   .Ic \&UE
   macro, an
   .Xr eqn 7
   right delimiter or closing brace, or the end of an equation, table, or
   .Xr roff 7
   conditional request is encountered but no matching block is open.
   The offending request or macro is discarded.
   .It Sy "fewer RS blocks open, skipping"
   .Pq man
 The  The
   .Ic \&RE
   macro is invoked with an argument, but less than the specified number of
   .Ic \&RS
   blocks is open.
   The
   .Ic \&RE
   macro is discarded.
   .It Sy "inserting missing end of block"
   .Pq mdoc , tbl
   Various
   .Xr mdoc 7
   macros as well as tables require explicit closing by dedicated macros.
   A block that doesn't support bad nesting
   ends before all of its children are properly closed.
   The open child nodes are closed implicitly.
   .It Sy "scope open on exit"
   .Pq mdoc , man , eqn , tbl , roff
   At the end of the document, an explicit
   .Xr mdoc 7
   block, a
 .Xr man 7  .Xr man 7
 .Sq IP  next-line scope or
   .Ic \&RS
   or
   .Ic \&UR
   block, an equation, table, or
   .Xr roff 7
   conditional or ignore block is still open.
   The open block is closed implicitly.
   .It Sy "escaped character not allowed in a name"
   .Pq roff
   Macro, string and register identifiers consist of printable,
   non-whitespace ASCII characters.
   Escape sequences and characters and strings expressed in terms of them
   cannot form part of a name.
   The first argument of an
   .Ic \&am ,
   .Ic \&as ,
   .Ic \&de ,
   .Ic \&ds ,
   .Ic \&nr ,
   or
   .Ic \&rr
   request, or any argument of an
   .Ic \&rm
   request, or the name of a request or user defined macro being called,
   is terminated by an escape sequence.
   In the cases of
   .Ic \&as ,
   .Ic \&ds ,
 and  and
 .Sq TP  .Ic \&nr ,
 lists render similarly.  the request has no effect at all.
   In the cases of
   .Ic \&am ,
   .Ic \&de ,
   .Ic \&rr ,
   and
   .Ic \&rm ,
   what was parsed up to this point is used as the arguments to the request,
   and the rest of the input line is discarded including the escape sequence.
   When parsing for a request or a user-defined macro name to be called,
   only the escape sequence is discarded.
   The characters preceding it are used as the request or macro name,
   the characters following it are used as the arguments to the request or macro.
   .It Sy "argument count wrong"
   .Pq mdoc , man , roff
   The indicated request or macro has too few or too many arguments.
   The syntax tree will contain the wrong number of arguments as given.
   Formatting behaviour depends on the specific request or macro in question.
   Note that the same message may also occur as a WARNING, see above.
   .It Sy "NOT IMPLEMENTED: Bd -file"
   .Pq mdoc
   For security reasons, the
   .Ic \&Bd
   macro does not support the
   .Fl file
   argument.
   By requesting the inclusion of a sensitive file, a malicious document
   might otherwise trick a privileged user into inadvertently displaying
   the file on the screen, revealing the file content to bystanders.
   The argument is ignored including the file name following it.
   .It Sy "missing list type, using -item"
   .Pq mdoc
   A
   .Ic \&Bl
   macro fails to specify the list type.
   .It Sy "missing manual name, using \(dq\(dq"
   .Pq mdoc
   The first call to
   .Ic \&Nm
   lacks the required argument.
   .It Sy "uname(3) system call failed, using UNKNOWN"
   .Pq mdoc
   The
   .Ic \&Os
   macro is called without arguments, and the
   .Xr uname 3
   system call failed.
   As a workaround,
   .Nm
   can be compiled with
   .Sm off
   .Fl D Cm OSNAME=\(dq\e\(dq Ar string Cm \e\(dq\(dq .
   .Sm on
   .It Sy "unknown standard specifier"
   .Pq mdoc
   An
   .Ic \&St
   macro has an unknown argument and is discarded.
   .It Sy "skipping request without numeric argument"
   .Pq roff , eqn
   An
   .Ic \&it
   request or an
   .Xr eqn 7
   .Ic \&size
   or
   .Ic \&gsize
   statement has a non-numeric or negative argument or no argument at all.
   The invalid request or statement is ignored.
   .It Sy "NOT IMPLEMENTED: .so with absolute path or \(dq..\(dq"
   .Pq roff
   For security reasons,
   .Nm
   allows
   .Ic \&so
   file inclusion requests only with relative paths
   and only without ascending to any parent directory.
   By requesting the inclusion of a sensitive file, a malicious document
   might otherwise trick a privileged user into inadvertently displaying
   the file on the screen, revealing the file content to bystanders.
   .Nm
   only shows the path as it appears behind
   .Ic \&so .
   .It Sy ".so request failed"
   .Pq roff
   Servicing a
   .Ic \&so
   request requires reading an external file, but the file could not be
   opened.
   .Nm
   only shows the path as it appears behind
   .Ic \&so .
   .It Sy "skipping all arguments"
   .Pq mdoc , man , eqn , roff
   An
   .Xr mdoc 7
   .Ic \&Bt ,
   .Ic \&Ed ,
   .Ic \&Ef ,
   .Ic \&Ek ,
   .Ic \&El ,
   .Ic \&Lp ,
   .Ic \&Pp ,
   .Ic \&Re ,
   .Ic \&Rs ,
   or
   .Ic \&Ud
   macro, an
   .Ic \&It
   macro in a list that don't support item heads, a
   .Xr man 7
   .Ic \&LP ,
   .Ic \&P ,
   or
   .Ic \&PP
   macro, an
   .Xr eqn 7
   .Ic \&EQ
   or
   .Ic \&EN
   macro, or a
   .Xr roff 7
   .Ic \&br ,
   .Ic \&fi ,
   or
   .Ic \&nf
   request or
   .Sq \&..
   block closing request is invoked with at least one argument.
   All arguments are ignored.
   .It Sy "skipping excess arguments"
   .Pq mdoc , man , roff
   The
   .Ic \&An
   macro is invoked with another argument after
   .Fl split
   or
   .Fl nosplit ,
   .Ic \&Fo
   is invoked with more than one argument,
   .Ic \&Bd ,
   .Ic \&Bk ,
   or
   .Ic \&Bl
   are invoked with invalid arguments, the
   .Ic \&RE
   macro is invoked with more than one argument
   or with a non-integer argument, the
   .Ic \&sp
   request is invoked with more than one argument, or a request of the
   .Ic \&de
   family is invoked with more than two arguments.
   The excess arguments are ignored.
 .El  .El
 .  .Ss Unsupported features
 .  .Bl -ohang
   .It Sy "input too large"
   .Pq mdoc , man
   Currently,
   .Nm
   cannot handle input files larger than its arbitrary size limit
   of 2^31 bytes (2 Gigabytes).
   Since useful manuals are always small, this is not a problem in practice.
   Parsing is aborted as soon as the condition is detected.
   .It Sy "unsupported control character"
   .Pq roff
   An ASCII control character supported by other
   .Xr roff 7
   implementations but not by
   .Nm
   was found in an input file.
   It is replaced by a question mark.
   .It Sy "unsupported roff request"
   .Pq roff
   An input file contains a
   .Xr roff 7
   request supported by GNU troff or Heirloom troff but not by
   .Nm ,
   and it is likely that this will cause information loss
   or considerable misformatting.
   .It Sy "eqn delim option in tbl"
   .Pq eqn , tbl
   The options line of a table defines equation delimiters.
   Any equation source code contained in the table will be printed unformatted.
   .It Sy "unsupported table layout modifier"
   .Pq tbl
   A table layout specification contains an
   .Sq Cm m
   modifier.
   The modifier is discarded.
   .It Sy "ignoring macro in table"
   .Pq tbl , mdoc , man
   A table contains an invocation of an
   .Xr mdoc 7
   or
   .Xr man 7
   macro or of an undefined macro.
   The macro is ignored, and its arguments are handled
   as if they were a text line.
   .El
 .Sh SEE ALSO  .Sh SEE ALSO
   .Xr apropos 1 ,
   .Xr man 1 ,
   .Xr eqn 7 ,
 .Xr man 7 ,  .Xr man 7 ,
 .Xr mandoc_char 7 ,  .Xr mandoc_char 7 ,
 .Xr mdoc 7  .Xr mdoc 7 ,
 .  .Xr roff 7 ,
   .Xr tbl 7
 .Sh AUTHORS  .Sh AUTHORS
 The  The
 .Nm  .Nm
 utility was written by  utility was written by
 .An Kristaps Dzonsons Aq kristaps@kth.se .  .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
 .  and is maintained by
 .  .An Ingo Schwarze Aq Mt schwarze@openbsd.org .
 .Sh CAVEATS  .Sh BUGS
 The  
 .Fl T Ns Ar html  
 and  
 .Fl T Ns Ar xhtml  
 CSS2 styling used for  
 .Fl m Ns Ar doc  
 input lists does not render properly in older browsers, such as Internet  
 Explorer 6 and earlier.  
 .  
 .Pp  
 In  In
 .Fl T Ns Ar html  .Fl T Ns Cm html ,
 and  
 .Fl T Ns Ar xhtml ,  
 the maximum size of an element attribute is determined by  the maximum size of an element attribute is determined by
 .Dv BUFSIZ ,  .Dv BUFSIZ ,
 which is usually 1024 bytes.  which is usually 1024 bytes.
 Be aware of this when setting long link  Be aware of this when setting long link
 formats, e.g.,  formats such as
 .Fl O Ns Ar style=really/long/link .  .Fl O Ns Cm style Ns = Ns Ar really/long/link .
 .  
 .Pp  
 The  
 .Fl T Ns Ar html  
 and  
 .Fl T Ns Ar xhtml  
 output modes don't render the  
 .Sq \es  
 font size escape documented in  
 .Xr mdoc 7  
 and  
 .Xr man 7 .  
 .  
 .Pp  
 Nesting elements within next-line element scopes of  
 .Fl m Ns Ar an ,  
 such as  
 .Sq br  
 within an empty  
 .Sq B ,  
 will confuse  
 .Fl T Ns Ar html  
 and  
 .Fl T Ns Ar xhtml  
 and cause them to forget the formatting of the prior next-line scope.  
 .  
 .Pp  
 The  
 .Sq i  
 macro in  
 .Fl m Ns Ar an  
 should italicise all subsequent text if a line argument is not provided.  
 This behaviour is not implemented.  
 .  
 The  
 .Sq \(aq  
 control character is an alias for the standard macro control character  
 and does not emit a line-break as stipulated in GNU troff.  
Legend:
Removed from v.1.57  
changed lines
  Added in v.1.148
CVSweb