+- support translated section names
+ e.g. x11/scrotwm scrotwm_es.1:21:2: error: NAME section must be first
+ that one uses NOMBRE because it is spanish...
+ deraadt tends to think that section-dependent macro behaviour
+ is a bad idea in the first place, so this may be irrelevant
+ loc ** exist ** algo ** size * imp **
+
+- When there is free text in the SYNOPSIS and that free text contains
+ the .Nm macro, groff somehow understands to treat the .Nm as an in-line
+ macro, while mandoc treats it as a block macro and breaks the line.
+ No idea how the logic for distinguishing in-line and block instances
+ should be, needs investigation.
+ uqs@ Thu, 2 Jun 2011 11:03:51 +0200
+ uqs@ Thu, 2 Jun 2011 11:33:35 +0200
+ loc * exist ** algo *** size * imp **
+
+--- missing man features -----------------------------------------------
+
+- groff_www(7) .MTO and .URL
+ These macros were used by the GNU grep(1) man page.
+ The groff_www(7) manual page itself uses them, too.
+ We should probably *not* add them to mandoc.
+ Just mentioning this here to keep track of the abuse.
+ Laura Morales <lauretas at mail dot com> 20 Apr 2018 07:33:02 +0200
+ loc ** exist * algo * size ** imp *
+
+--- missing tbl features -----------------------------------------------
+
+- vertical centering in cells vertically spanned with ^
+ pali dot rohar at gmail dot com 16 Jul 2018 13:03:35 +0200
+ loc * exist *** algo *** size ** imp *
+
+- support mdoc(7) and man(7) macros inside tbl(7) code;
+ probably requires the parser reorg and letting tbl(7)
+ use roff_node such that macro sets can mix;
+ informed by bapt@ that FreeBSD needs this: 3 Jan 2015 23:32:23 +0100
+ loc *** exist ** algo *** size ** imp ***
+
+- look at the POSIX manuals in the books/man-pages-posix port,
+ they use some unsupported tbl(7) features, mostly macros in tbl(7).
+ loc * exist ** algo ** size ** imp ***
+
+- look what Joerg Schilling manual pages use
+ Thu, 19 Mar 2015 18:31:48 +0100
+
+--- missing eqn features -----------------------------------------------
+
+- In a matrix, break the output line after each matrix line.
+ Found in the discussion at CDBUG 2015. Suggested by Avi Weinstock.
+ This may not be the ideal solution after all: eqn(7) matrices
+ are lists of columns, so Avi's proposal would show each *column*
+ on its own *line*, which is likely to cause confusion.
+ A better solution, but much harder to implement, would be to
+ actually show the coordinates of column vectors on different
+ terminal output lines, using the clumnated output facilities
+ developed for .Bl -tag, .Bl -column, and also used for tbl(7).
+ loc * exist * algo ** size ** imp **
+
+- The "size" keyword is parsed, but ignored by the formatter.
+ loc * exist * algo * size * imp *
+
+- The spacing characters `~', `^', and tab are currently ignored,
+ see User's Guide (Second Edition) page 2 section 4.
+ loc * exist * algo ** size * imp **
+
+- Mark and lineup are parsed and ignored,
+ see User's Guide (Second Edition) page 5 section 15.
+ loc ** exist ** algo ** size ** imp **
+
+- GNU eqn converts some operators to special characters, for example,
+ input HYPHEN-MINUS becomes output \(mi, unless it is part of a
+ quoted word. mandoc(1) only does this when the operator is
+ surrounded by blanks, not when it is part of an unquoted word.
+ Also, check whether there are more such cases (e.g., +?).
+ reported by bentley@ 20 Jun 2017 02:04:29 -0600
+ loc * exist ** algo ** size * imp *
+
+- Primes, opprime, and '
+ bentley@ Thu, 13 Jul 2017 23:14:20 -0600
+
+--- missing misc features ----------------------------------------------
+
+- man -ks 1,8 route; kn@ Jul 13, 2018 orally
+
+- italic correction (\/) in PostScript mode
+ Werner LEMBERG on groff at gnu dot org Sun, 10 Nov 2013 12:47:46
+ loc ** exist ** algo * size * imp *
+
+- change the default PAGER to more -Es and use the pager
+ even for apropos title line output; req by bapt@
+ loc * exist * algo * size * imp ***
+
+- clean up escape sequence handling, creating three classes:
+ (1) fully implemented, or parsed and ignored without loss of content
+ (2) unimplemented, potentially causing loss of content
+ or serious mangling of formatting (e.g. \n) -> ERROR
+ see textproc/mgdiff(1) for nice examples
+ (3) undefined, just output the character -> perhaps WARNING
+ loc *** exist ** algo ** size ** imp *** (parser reorg helps)
+
+- kettenis wants base roff, ms, and me Fri, 1 Jan 2010 22:13:15 +0100 (CET)
+ loc ** exist ** algo ** size *** imp *
+
+--- compatibility checks -----------------------------------------------
+
+- is .Bk implemented correctly in modern groff?
+ sobrado@ Tue, 19 Apr 2011 22:12:55 +0200
+
+- compare output to Heirloom roff, Solaris roff, and
+ http://repo.or.cz/w/neatroff.git http://litcave.rudi.ir/
+
+- look at AT&T DWB http://www2.research.att.com/sw/download
+ Carsten Kunze <carsten dot kunze at arcor dot de> has patches
+ Mon, 4 Aug 2014 17:01:28 +0200
+ ported version: https://github.com/n-t-roff/DWB3.3
+ Carsten Kunze Wed, 22 Apr 2015 11:21:43 +0200
+
+- look at pages generated from reStructeredText, e.g. devel/mercurial hg(1)
+ These are a weird mixture of man(7) and custom autogenerated low-level
+ roff stuff. Figure out to what extent we can cope.
+ For details, see http://docutils.sourceforge.net/rst.html
+ noted by stsp@ Sat, 24 Apr 2010 09:17:55 +0200
+ reminded by nicm@ Mon, 3 May 2010 09:52:41 +0100
+
+- look at pages generated from ronn(1) github.com/rtomayko/ronn
+ (based on markdown)
+
+- look at pages generated from Texinfo source by yat2m, e.g. security/gnupg
+ First impression is not that bad.
+
+- look at pages generated by pandoc; see
+ https://github.com/jgm/pandoc/blob/master/src/Text/Pandoc/Writers/Man.hs
+ porting planned by kili@ Thu, 19 Jun 2014 19:46:28 +0200
+
+- check compatibility with Plan9:
+ http://swtch.com/usr/local/plan9/tmac/tmac.an
+ http://swtch.com/plan9port/man/man7/man.html
+ "Anthony J. Bentley" <anthonyjbentley@gmail.com> 28 Dec 2010 21:58:40 -0700