===================================================================
RCS file: /cvs/mandoc/mandoc.1,v
retrieving revision 1.148
retrieving revision 1.187
diff -u -p -r1.148 -r1.187
--- mandoc/mandoc.1	2015/02/06 08:28:35	1.148
+++ mandoc/mandoc.1	2017/05/17 23:20:32	1.187
@@ -1,7 +1,7 @@
-.\"	$Id: mandoc.1,v 1.148 2015/02/06 08:28:35 schwarze Exp $
+.\"	$Id: mandoc.1,v 1.187 2017/05/17 23:20:32 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
-.\" Copyright (c) 2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -15,23 +15,21 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: February 6 2015 $
+.Dd $Mdocdate: May 17 2017 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
 .Nm mandoc
-.Nd format and display UNIX manuals
+.Nd format manual pages
 .Sh SYNOPSIS
 .Nm mandoc
-.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 O Ns Ar option
-.Op Fl T Ns Ar output
-.Op Fl W Ns Ar level
+.Op Fl ac
+.Op Fl I Cm os Ns = Ns Ar name
+.Op Fl K Ar encoding
+.Op Fl mdoc | man
+.Op Fl O Ar options
+.Op Fl T Ar output
+.Op Fl W Ar level
 .Op Ar
 .Sh DESCRIPTION
 The
@@ -46,10 +44,8 @@ reads
 .Xr mdoc 7
 or
 .Xr man 7
-text from stdin, implying
-.Fl m Ns Cm andoc ,
-and produces
-.Fl T Ns Cm locale
+text from stdin and produces
+.Fl T Cm locale
 output.
 .Pp
 The options are as follows:
@@ -69,31 +65,17 @@ 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
+.It Fl I Cm os Ns = Ns Ar name
 Override the default operating system
 .Ar name
 for the
 .Xr mdoc 7
-.Sq \&Os
+.Ic \&Os
 and for the
 .Xr man 7
-.Sq \&TH
+.Ic \&TH
 macro.
-.It Fl h
-Display only the SYNOPSIS lines.
-Implies
-.Fl c .
-.It Fl K Ns Ar encoding
+.It Fl K Ar encoding
 Specify the input encoding.
 The supported
 .Ar encoding
@@ -102,70 +84,76 @@ arguments are
 .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
+If not specified, autodetection uses the first match in the following
+list:
+.Bl -enum
+.It
+If the first three bytes of the input file are the UTF-8 byte order
+mark (BOM, 0xefbbbf), input is interpreted as
+.Cm utf-8 .
+.It
+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
+.Pp
+then input is interpreted according to
+.Ar encoding .
+.It
+If the first non-ASCII byte in the file introduces a valid UTF-8
+sequence, input is interpreted as
+.Cm utf-8 .
+.It
+Otherwise, input is interpreted as
+.Cm iso-8859-1 .
 .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
-Input format.
-See
-.Sx Input Formats
-for available formats.
-Defaults to
-.Fl m Ns Cm andoc .
-.It Fl O Ns Ar option
+.It Fl mdoc | man
+With
+.Fl mdoc ,
+all input files are interpreted as
+.Xr mdoc 7 .
+With
+.Fl man ,
+all input files are interpreted as
+.Xr man 7 .
+By default, the input language is automatically detected for each file:
+if the the first macro is
+.Ic \&Dd
+or
+.Ic \&Dt ,
+the
+.Xr mdoc 7
+parser is used; otherwise, the
+.Xr man 7
+parser is used.
+With other arguments,
+.Fl m
+is silently ignored.
+.It Fl O Ar options
 Comma-separated output options.
-.It Fl T Ns Ar output
+.It Fl T Ar output
 Output format.
 See
 .Sx Output Formats
 for available formats.
 Defaults to
-.Fl T Ns Cm locale .
-.It Fl V
-Print version and exit.
-.It Fl W Ns Ar level
+.Fl T Cm locale .
+.It Fl W Ar level
 Specify the minimum message
 .Ar level
 to be reported on the standard error output and to affect the exit status.
 The
 .Ar level
 can be
+.Cm style ,
 .Cm warning ,
 .Cm error ,
 or
 .Cm unsupp ;
 .Cm all
 is an alias for
-.Cm warning .
+.Cm style .
 By default,
 .Nm
 is silent.
@@ -176,7 +164,7 @@ and
 for details.
 .Pp
 The special option
-.Fl W Ns Cm stop
+.Fl W Cm stop
 tells
 .Nm
 to exit after parsing a file that causes warnings or errors of at least
@@ -187,7 +175,7 @@ If both a
 and
 .Cm stop
 are requested, they can be joined with a comma, for example
-.Fl W Ns Cm error , Ns Cm stop .
+.Fl W Cm error , Ns Cm stop .
 .It Ar file
 Read input from zero or more files.
 If unspecified, reads from stdin.
@@ -196,6 +184,9 @@ If multiple files are specified,
 will halt with the first failed parse.
 .El
 .Pp
+The options
+.Fl fhklw
+are also supported and are documented in man(1).
 In
 .Fl f
 and
@@ -203,107 +194,75 @@ and
 mode,
 .Nm
 also supports the options
-.Fl CMmOSsw
+.Fl CMmOSs
 described in the
 .Xr apropos 1
 manual.
-.Ss Input Formats
-The
-.Nm
-utility accepts
-.Xr mdoc 7
-and
-.Xr man 7
-input with
-.Fl m Ns Cm doc
-and
-.Fl m Ns Cm an ,
-respectively.
-The
-.Xr mdoc 7
-format is
-.Em strongly
-recommended;
-.Xr man 7
-should only be used for legacy manuals.
-.Pp
-A third option,
-.Fl m Ns Cm andoc ,
-which is also the default, determines encoding on-the-fly: if the first
-non-comment macro is
-.Sq \&Dd
-or
-.Sq \&Dt ,
-the
-.Xr mdoc 7
-parser is used; otherwise, the
-.Xr man 7
-parser is used.
-.Pp
-If multiple
-files are specified with
-.Fl m Ns Cm andoc ,
-each has its file-type determined this way.
-If multiple files are
-specified and
-.Fl m Ns Cm doc
-or
-.Fl m Ns Cm an
-is specified, then this format is used exclusively.
+The options
+.Fl fkl
+are mutually exclusive and override each other.
 .Ss Output Formats
 The
 .Nm
 utility accepts the following
 .Fl T
 arguments, which correspond to output modes:
-.Bl -tag -width "-Tlocale"
-.It Fl T Ns Cm ascii
+.Bl -tag -width "-T markdown"
+.It Fl T Cm ascii
 Produce 7-bit ASCII output.
 See
 .Sx ASCII Output .
-.It Fl T Ns Cm html
+.It Fl T Cm html
 Produce HTML5, CSS1, and MathML output.
 See
 .Sx HTML Output .
-.It Fl T Ns Cm lint
+.It Fl T Cm lint
 Parse only: produce no output.
 Implies
-.Fl W Ns Cm warning .
-.It Fl T Ns Cm locale
+.Fl W Cm warning .
+.It Fl T Cm locale
 Encode output using the current locale.
 This is the default.
 See
 .Sx Locale Output .
-.It Fl T Ns Cm man
+.It Fl T Cm man
 Produce
 .Xr man 7
 format output.
 See
 .Sx Man Output .
-.It Fl T Ns Cm pdf
+.It Fl T Cm markdown
+Produce output in
+.Sy markdown
+format.
+See
+.Sx Markdown Output .
+.It Fl T Cm pdf
 Produce PDF output.
 See
 .Sx PDF Output .
-.It Fl T Ns Cm ps
+.It Fl T Cm ps
 Produce PostScript output.
 See
 .Sx PostScript Output .
-.It Fl T Ns Cm tree
+.It Fl T Cm tree
 Produce an indented parse tree.
-.It Fl T Ns Cm utf8
+See
+.Sx Syntax tree output .
+.It Fl T Cm utf8
 Encode output in the UTF\-8 multi-byte format.
 See
 .Sx UTF\-8 Output .
-.It Fl T Ns Cm xhtml
+.It Fl T Cm xhtml
 This is a synonym for
-.Fl T Ns Cm html .
+.Fl T Cm html .
 .El
 .Pp
 If multiple input files are specified, these will be processed by the
 corresponding filter in-order.
 .Ss ASCII Output
 Output produced by
-.Fl T Ns Cm ascii
+.Fl T Cm ascii
 is rendered in standard 7-bit ASCII documented in
 .Xr ascii 7 .
 .Pp
@@ -345,7 +304,7 @@ which will normalise to \(>=58.
 .El
 .Ss HTML Output
 Output produced by
-.Fl T Ns Cm html
+.Fl T Cm html
 conforms to HTML5 using optional self-closing tags.
 Default styles use only CSS1.
 Equations rendered from
@@ -353,11 +312,11 @@ Equations rendered from
 blocks use MathML.
 .Pp
 The
-.Pa example.style.css
+.Pa mandoc.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
+.Fl O Cm style ,
+.Fl T Cm html
 defaults to simple output (via an embedded style-sheet)
 readable in any graphical or text-based web
 browser.
@@ -381,7 +340,7 @@ The string
 for example,
 .Ar ../src/%I.html ,
 is used as a template for linked header files (usually via the
-.Sq \&In
+.Ic \&In
 macro).
 Instances of
 .Sq \&%I
@@ -394,7 +353,7 @@ The string
 for example,
 .Ar ../html%S/%N.%S.html ,
 is used as a template for linked manuals (usually via the
-.Sq \&Xr
+.Ic \&Xr
 macro).
 Instances of
 .Sq \&%N
@@ -413,13 +372,13 @@ relative URI.
 .El
 .Ss Locale Output
 Locale-depending output encoding is triggered with
-.Fl T Ns Cm locale .
+.Fl T Cm locale .
 This is the default.
 .Pp
 This option is not available on all systems: systems without locale
 support, or those whose internal representation is not natively UCS-4,
 will fall back to
-.Fl T Ns Cm ascii .
+.Fl T Cm ascii .
 See
 .Sx ASCII Output
 for font style specification and available command-line arguments.
@@ -440,16 +399,50 @@ If the input format is
 .Xr man 7 ,
 the input is copied to the output, expanding any
 .Xr roff 7
-.Sq so
+.Ic 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 Markdown Output
+Translate
+.Xr mdoc 7
+input to the
+.Sy markdown
+format conforming to
+.Lk http://daringfireball.net/projects/markdown/syntax.text\
+ "John Gruber's 2004 specification" .
+The output also almost conforms to the
+.Lk http://commonmark.org/ CommonMark
+specification.
+.Pp
+The character set used for the markdown output is ASCII.
+Non-ASCII characters are encoded as HTML entities.
+Since that is not possible in literal font contexts, because these
+are rendered as code spans and code blocks in the markdown output,
+non-ASCII characters are transliterated to ASCII approximations in
+these contexts.
+.Pp
+Markdown is a very weak markup language, so all semantic markup is
+lost, and even part of the presentational markup may be lost.
+Do not use this as an intermediate step in converting to HTML;
+instead, use
+.Fl T Cm html
+directly.
+.Pp
+The
+.Xr man 7 ,
+.Xr tbl 7 ,
+and
+.Xr eqn 7
+input languages are not supported by
+.Fl T Cm markdown
+output mode.
 .Ss PDF Output
 PDF-1.1 output may be generated by
-.Fl T Ns Cm pdf .
+.Fl T Cm pdf .
 See
 .Sx PostScript Output
 for
@@ -459,7 +452,7 @@ arguments and defaults.
 PostScript
 .Qq Adobe-3.0
 Level-2 pages may be generated by
-.Fl T Ns Cm ps .
+.Fl T 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.
@@ -491,25 +484,105 @@ is used.
 .El
 .Ss UTF\-8 Output
 Use
-.Fl T Ns Cm utf8
+.Fl T Cm utf8
 to force a UTF\-8 locale.
 See
 .Sx Locale Output
 for details and options.
+.Ss Syntax tree output
+Use
+.Fl T Cm tree
+to show a human readable representation of the syntax tree.
+It is useful for debugging the source code of manual pages.
+The exact format is subject to change, so don't write parsers for it.
+.Pp
+The first paragraph shows meta data found in the
+.Xr mdoc 7
+prologue, on the
+.Xr man 7
+.Ic \&TH
+line, or the fallbacks used.
+.Pp
+In the tree dump, each output line shows one syntax tree node.
+Child nodes are indented with respect to their parent node.
+The columns are:
+.Pp
+.Bl -enum -compact
+.It
+For macro nodes, the macro name; for text and
+.Xr tbl 7
+nodes, the content.
+There is a special format for
+.Xr eqn 7
+nodes.
+.It
+Node type (text, elem, block, head, body, body-end, tail, tbl, eqn).
+.It
+Flags:
+.Bl -dash -compact
+.It
+An opening parenthesis if the node is an opening delimiter.
+.It
+An asterisk if the node starts a new input line.
+.It
+The input line number (starting at one).
+.It
+A colon.
+.It
+The input column number (starting at one).
+.It
+A closing parenthesis if the node is a closing delimiter.
+.It
+A full stop if the node ends a sentence.
+.It
+BROKEN if the node is a block broken by another block.
+.It
+NOSRC if the node is not in the input file,
+but automatically generated from macros.
+.It
+NOPRT if the node is not supposed to generate output
+for any output format.
+.El
+.El
+.Pp
+The following
+.Fl O
+argument is accepted:
+.Bl -tag -width Ds
+.It Cm noval
+Skip validation and show the unvalidated syntax tree.
+This can help to find out whether a given behaviour is caused by
+the parser or by the validator.
+Meta data is not available in this case.
+.El
 .Sh ENVIRONMENT
 .Bl -tag -width MANPAGER
 .It Ev MANPAGER
 Any non-empty value of the environment variable
 .Ev MANPAGER
-will be used instead of the standard pagination program,
-.Xr more 1 .
+is used instead of the standard pagination program,
+.Xr more 1 ;
+see
+.Xr man 1
+for details.
+Only used if
+.Fl a
+or
+.Fl l
+is specified.
 .It Ev PAGER
 Specifies the pagination program to use when
 .Ev MANPAGER
 is not defined.
 If neither PAGER nor MANPAGER is defined,
-.Pa /usr/bin/more Fl s
-will be used.
+.Xr more 1
+.Fl s
+is used.
+Only used if
+.Fl a
+or
+.Fl l
+is specified.
 .El
 .Sh EXIT STATUS
 The
@@ -522,27 +595,32 @@ option:
 .Pp
 .Bl -tag -width Ds -compact
 .It 0
-No warnings or errors occurred, or those that did were ignored because
-they were lower than the requested
+No style suggestions, warnings or errors occurred, or those that
+did were ignored because they were lower than the requested
 .Ar level .
+.It 1
+At least one style suggestion occurred, but no warning or error, and
+.Fl W Cm style
+was specified.
 .It 2
 At least one warning occurred, but no error, and
-.Fl W Ns Cm warning
+.Fl W Cm warning
+or
+.Fl W Cm style
 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.
+.Fl W Cm error
+or a lower
+.Ar level
+was requested.
 .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.
+.Fl W Cm unsupp
+or a lower
+.Ar level
+was requested.
 .It 5
 Invalid command line arguments were specified.
 No input files have been read.
@@ -555,28 +633,27 @@ to exit at once, possibly in the middle of parsing or 
 .El
 .Pp
 Note that selecting
-.Fl T Ns Cm lint
+.Fl T Cm lint
 output mode implies
-.Fl W Ns Cm warning .
+.Fl W Cm warning .
 .Sh EXAMPLES
 To page manuals to the terminal:
 .Pp
-.Dl $ mandoc \-Wall,stop mandoc.1 2\*(Gt&1 | less
-.Dl $ mandoc mandoc.1 mdoc.3 mdoc.7 | less
+.Dl $ mandoc -l mandoc.1 man.1 apropos.1 makewhatis.8
 .Pp
 To produce HTML manuals with
-.Ar style.css
+.Pa mandoc.css
 as the style-sheet:
 .Pp
-.Dl $ mandoc \-Thtml -Ostyle=style.css mdoc.7 \*(Gt mdoc.7.html
+.Dl $ mandoc \-T html -O style=mandoc.css mdoc.7 \*(Gt mdoc.7.html
 .Pp
 To check over a large set of manuals:
 .Pp
-.Dl $ mandoc \-Tlint `find /usr/src -name \e*\e.[1-9]`
+.Dl $ mandoc \-T lint \(gafind /usr/src -name \e*\e.[1-9]\(ga
 .Pp
 To produce a series of PostScript manuals for A4 paper:
 .Pp
-.Dl $ mandoc \-Tps \-Opaper=a4 mdoc.7 man.7 \*(Gt manuals.ps
+.Dl $ mandoc \-T ps \-O paper=a4 mdoc.7 man.7 \*(Gt manuals.ps
 .Pp
 Convert a modern
 .Xr mdoc 7
@@ -586,7 +663,7 @@ format, for use on systems lacking an
 .Xr mdoc 7
 parser:
 .Pp
-.Dl $ mandoc \-Tman foo.mdoc \*(Gt foo.man
+.Dl $ mandoc \-T man foo.mdoc \*(Gt foo.man
 .Sh DIAGNOSTICS
 Messages displayed by
 .Nm
@@ -642,9 +719,22 @@ rendering can be produced.
 Documents causing warnings may render poorly when using other
 formatting tools instead of
 .Nm .
+.It Cm style
+An input file uses dubious or discouraged style.
+This is not a complaint about the syntax, and probably neither
+formatting nor portability are in danger.
+While great care is taken to avoid false positives on the higher
+message levels, the
+.Cm style
+level tries to reduce the probability that issues go unnoticed,
+so it may occasionally issue bogus suggestions.
+Please use your good judgement to decide whether any particular
+.Cm style
+suggestion really justifies a change to the input file.
 .El
 .Pp
 Messages of the
+.Cm style ,
 .Cm warning ,
 .Cm error ,
 and
@@ -653,7 +743,7 @@ levels except those about non-existent or unreadable i
 are hidden unless their level, or a lower level, is requested using a
 .Fl W
 option or
-.Fl T Ns Cm lint
+.Fl T Cm lint
 output mode.
 .Ss Warnings related to the document prologue
 .Bl -ohang
@@ -729,9 +819,9 @@ macro occurs after some non-prologue macro, but still 
 .Pq mdoc
 The
 .Ic \&Dt
-macro can only occur before the first non-prologue macro
-because traditional formatters write the page header
-before parsing the document body.
+macro appears after the first non-prologue macro.
+Traditional formatters cannot handle this because
+they write the page header before parsing the document body.
 Even though this technical restriction does not apply to
 .Nm ,
 traditional semantics is preserved.
@@ -773,23 +863,48 @@ This may confuse
 .Xr makewhatis 8
 and
 .Xr apropos 1 .
-.It Sy "bad NAME section contents"
+.It Sy "NAME section without Nm before Nd"
 .Pq mdoc
-The last node in the NAME section is not an
+The NAME section does not contain any
+.Ic \&Nm
+child macro before the first
 .Ic \&Nd
-macro, or any preceding macro is not
-.Ic \&Nm ,
-or the NAME section is completely empty.
-This may confuse
-.Xr makewhatis 8
+macro.
+.It Sy "NAME section without description"
+.Pq mdoc
+The NAME section lacks the mandatory
+.Ic \&Nd
+child macro.
+.It Sy "description not at the end of NAME"
+.Pq mdoc
+The NAME section does contain an
+.Ic \&Nd
+child macro, but other content follows it.
+.It Sy "bad NAME section content"
+.Pq mdoc
+The NAME section contains plain text or macros other than
+.Ic \&Nm
 and
-.Xr apropos 1 .
+.Ic \&Nd .
+.It Sy "missing comma before name"
+.Pq mdoc
+The NAME section contains an
+.Ic \&Nm
+macro that is neither the first one nor preceded by a comma.
 .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 "description line outside NAME section"
+.Pq mdoc
+An
+.Ic \&Nd
+macro appears outside the NAME section.
+The arguments are printed anyway and the following text is used for
+.Xr apropos 1 ,
+but none of that behaviour is portable.
 .It Sy "sections out of conventional order"
 .Pq mdoc
 A standard section occurs after another section it usually precedes.
@@ -809,7 +924,7 @@ In the SEE ALSO section, an
 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.
+macros referring to the same section are out of alphabetical order.
 .It Sy "unusual Xr punctuation"
 .Pq mdoc
 In the SEE ALSO section, punctuation between two
@@ -836,7 +951,7 @@ manual for replacements.
 .Pq mdoc
 The name of a macro that is not callable appears on a macro line.
 It is printed verbatim.
-If the intention is to call it, move it to its own line;
+If the intention is to call it, move it to its own input line;
 otherwise, escape it by prepending
 .Sq \e& .
 .It Sy "skipping paragraph macro"
@@ -929,13 +1044,6 @@ 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
@@ -1015,7 +1123,7 @@ or
 .Ic \&Bl
 .Fl offset
 or
-.Fl width.
+.Fl width .
 .It Sy "missing display type, using -ragged"
 .Pq mdoc
 The
@@ -1080,21 +1188,18 @@ list, an
 .Ic \&It
 block is empty.
 An empty list item is shown.
-.It Sy "missing font type"
+.It Sy "missing font type, using \efR"
 .Pq mdoc
 A
 .Ic \&Bf
 macro has no argument.
-It switches to the default font,
-.Cm \efR .
-.It Sy "unknown font type"
+It switches to the default font.
+.It Sy "unknown font type, using \efR"
 .Pq mdoc
 The
 .Ic \&Bf
 argument is invalid.
-The default font
-.Cm \efR
-is used instead.
+The default font is used instead.
 .It Sy "nothing follows prefix"
 .Pq mdoc
 A
@@ -1111,6 +1216,13 @@ 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 section argument"
+.Pq mdoc
+An
+.Ic \&Xr
+macro lacks its second, section number argument.
+The first argument, i.e. the name, is printed, but without subsequent
+parentheses.
 .It Sy "missing -std argument, adding it"
 .Pq mdoc
 An
@@ -1125,6 +1237,18 @@ The
 utility assumes
 .Fl std
 even when it is not specified, but other implementations may not.
+.It Sy "missing option string, using \(dq\(dq"
+.Pq man
+The
+.Ic \&OP
+macro is invoked without any argument.
+An empty pair of square brackets is shown.
+.It Sy "missing resource identifier, using \(dq\(dq"
+.Pq man
+The
+.Ic \&UR
+macro is invoked without any argument.
+An empty pair of angle brackets is shown.
 .It Sy "missing eqn box, using \(dq\(dq"
 .Pq eqn
 A diacritic mark or a binary operator is found,
@@ -1189,6 +1313,15 @@ list has a
 .Fl width
 argument.
 That has no effect.
+.It Sy "wrong number of cells"
+In a line of a
+.Ic \&Bl Fl column
+list, the number of tabs or
+.Ic \&Ta
+macros is less than the number expected from the list header line
+or exceeds the expected number by more than one.
+Missing cells remain empty, and all cells exceeding the number of
+columns are joined into one single cell.
 .It Sy "unknown AT&T UNIX version"
 .Pq mdoc
 An
@@ -1240,6 +1373,12 @@ request or a
 layout modifier has an unknown
 .Ar font
 argument.
+.It Sy "odd number of characters in request"
+.Pq roff
+A
+.Ic \&tr
+request contains an odd number of characters.
+The last character is mapped to the blank character.
 .El
 .Ss "Warnings related to plain text"
 .Bl -ohang
@@ -1266,6 +1405,10 @@ it is hard to predict which tab stop position the tab 
 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 "new sentence, new line"
+.Pq mdoc
+A new sentence starts in the middle of a text line.
+Start it on a new input line to help formatters produce correct spacing.
 .It Sy "bad comment style"
 .Pq roff
 Comment lines start with a dot, a backslash, and a double-quote character.
@@ -1476,7 +1619,7 @@ macros as well as tables require explicit closing by d
 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"
+.It Sy "appending missing end of block"
 .Pq mdoc , man , eqn , tbl , roff
 At the end of the document, an explicit
 .Xr mdoc 7
@@ -1526,12 +1669,6 @@ When parsing for a request or a user-defined macro nam
 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
@@ -1543,6 +1680,13 @@ By requesting the inclusion of a sensitive file, a mal
 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 "skipping display without arguments"
+.Pq mdoc
+A
+.Ic \&Bd
+block macro does not have any arguments.
+The block is discarded, and the block content is displayed in
+whatever mode was active before the block.
 .It Sy "missing list type, using -item"
 .Pq mdoc
 A
@@ -1551,8 +1695,8 @@ 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.
+.Ic \&Nm ,
+or any call in the NAME section, lacks the required argument.
 .It Sy "uname(3) system call failed, using UNKNOWN"
 .Pq mdoc
 The
@@ -1645,26 +1789,44 @@ block closing request is invoked with at least one arg
 All arguments are ignored.
 .It Sy "skipping excess arguments"
 .Pq mdoc , man , roff
-The
+A macro or request is invoked with too many arguments:
+.Bl -dash -offset 2n -width 2n -compact
+.It
+.Ic \&Fo ,
+.Ic \&PD ,
+.Ic \&RS ,
+.Ic \&UR ,
+.Ic \&ft ,
+or
+.Ic \&sp
+with more than one argument
+.It
 .Ic \&An
-macro is invoked with another argument after
+with another argument after
 .Fl split
 or
-.Fl nosplit ,
-.Ic \&Fo
-is invoked with more than one argument,
+.Fl nosplit
+.It
+.Ic \&RE
+with more than one argument or with a non-integer argument
+.It
+.Ic \&OP
+or a request of the
+.Ic \&de
+family with more than two arguments
+.It
+.Ic \&Dt
+with more than three arguments
+.It
+.Ic \&TH
+with more than five arguments
+.It
 .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.
+with invalid arguments
+.El
 The excess arguments are ignored.
 .El
 .Ss Unsupported features
@@ -1722,19 +1884,24 @@ as if they were a text line.
 .Xr mdoc 7 ,
 .Xr roff 7 ,
 .Xr tbl 7
+.Sh HISTORY
+The
+.Nm
+utility first appeared in
+.Ox 4.8 .
+The option
+.Fl I
+appeared in
+.Ox 5.2 ,
+and
+.Fl aCcfhKklMSsw
+in
+.Ox 5.7 .
 .Sh AUTHORS
+.An -nosplit
 The
 .Nm
 utility was written by
 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
 and is maintained by
 .An Ingo Schwarze Aq Mt schwarze@openbsd.org .
-.Sh BUGS
-In
-.Fl T Ns Cm html ,
-the maximum size of an element attribute is determined by
-.Dv BUFSIZ ,
-which is usually 1024 bytes.
-Be aware of this when setting long link
-formats such as
-.Fl O Ns Cm style Ns = Ns Ar really/long/link .