+- .Rv (and probably .Ex) print different text if an `Nm' has been named
+ or not (run a manual without `Nm blah' to see this). I'm not sure
+ that this exists in the wild, but it's still an error.
+
+- In .Bl -bullet, the groff bullet is "+\b+\bo\bo", the mandoc bullet
+ is just "o\bo".
+ see for example OpenBSD ksh(1)
+
+- .Pp between two .It in .Bl -column should produce one,
+ not two blank lines, see e.g. login.conf(5).
+ reported by jmc@ Sun, 17 Apr 2011 14:04:58 +0059
+ reported again by sthen@ Wed, 18 Jan 2012 02:09:39 +0000 (UTC)
+
+- If the *first* line after .It is .Pp, break the line right after
+ the tag, do not pad with space characters before breaking.
+ See the description of the a, c, and i commands in sed(1).
+
+- If the first line after .It is .D1, do not assert a blank line
+ in between, see for example tmux(1).
+ reported by nicm@ 13 Jan 2011 00:18:57 +0000
+
+- Trailing punctuation after .It should trigger EOS spacing.
+ reported by Nicolas Joly Sat, 17 Nov 2012 11:49:54 +0100
+ Probably, this should be fixed somewhere in termp_it_pre(), not sure.
+
+- .Nx 1.0a
+ should be "NetBSD 1.0A", not "NetBSD 1.0a",
+ see OpenBSD ccdconfig(8).
+
+- In .Bl -tag, if a tag exceeds the right margin and must be continued
+ on the next line, it must be indented by -width, not width+1;
+ see "rule block|pass" in OpenBSD ifconfig(8).
+
+- When the -width string contains macros, the macros must be rendered
+ before measuring the width, for example
+ .Bl -tag -width ".Dv message"
+ in magic(5), located in src/usr.bin/file, is the same
+ as -width 7n, not -width 11n.
+ The same applies to .Bl -column column widths;
+ reported again by Nicolas Joly Thu, 1 Mar 2012 13:41:26 +0100 via wiz@ 5 Mar
+ reported again by Franco Fichtner Fri, 27 Sep 2013 21:02:28 +0200
+ An easy partial fix would be to just skip the first word if it starts
+ with a dot, including any following white space, when measuring.
+
+- The \& zero-width character counts as output.
+ That is, when it is alone on a line between two .Pp,
+ we want three blank lines, not two as in mandoc.
+
+- Header lines of excessive length:
+ Port OpenBSD man_term.c rev. 1.25 to mdoc_term.c
+ and document it in mdoc(7) and man(7) COMPATIBILITY
+ found while talking to Chris Bennett
+
+- trailing whitespace must be ignored even when followed by a font escape,
+ see for example
+ makes
+ \fBdig \fR
+ operate in batch mode
+ in dig(1).
+
+************************************************************************
+* warning issues
+************************************************************************
+
+- check that MANDOCERR_BADTAB is thrown in the right cases,
+ i.e. when finding a literal tab character in fill mode,
+ and possibly change the wording of the warning message
+ to refer to fill mode, not literal mode
+ See the mail from Werner LEMBERG on the groff list,
+ Fri, 14 Feb 2014 18:54:42 +0100 (CET)