TODO

   1 ************************************************************************
   2 * Official mandoc TODO.
   3 * $Id: TODO,v 1.288 2019/03/04 11:40:09 schwarze Exp $
   4 ************************************************************************
   5
   6 Many issues are annotated for difficulty as follows:
   7
   8  - loc = locality of the issue
   9     *    single file issue, affects file only, or very few
  10     **   single module issue, affects several files of one module
  11     ***  cross-module issue, significantly impacts multiple modules
  12          and may require substantial changes to internal interfaces
  13  - exist = difficulty of the existing code in this area
  14     *    affected code is straightforward and easy to read and change
  15     **   affected code is somewhat complex, but once you understand
  16          the design, not particularly difficult to understand
  17     ***  affected code uses a special, exceptionally tricky design
  18  - algo = difficulty of the new algorithm to be written
  19     *    the required logic and code is straightforward
  20     **   the required logic is somewhat complex and needs a careful design
  21     ***  the required logic is exceptionally tricky,
  22          maybe an approach to solve that is not even known yet
  23  - size = the amount of code to be written or changed
  24     *    a small number of lines (at most 100, usually much less)
  25     **   a considerable amount of code (several dozen to a few hundred)
  26     ***  a large amount of code (many hundreds, maybe thousands)
  27  - imp = importance of the issue
  28     *    mostly for completeness
  29     **   would be nice to have
  30     ***  issue causes considerable inconvenience
  31
  32 Obviously, as the issues have not been solved yet, these annotations
  33 are mere guesses, and some may be wrong.
  34
  35 ************************************************************************
  36 * missing features
  37 ************************************************************************
  38
  39 --- missing roff features ----------------------------------------------
  40
  41 - .ad (adjust margins)
  42   .ad l -- adjust left margin only (flush left)
  43   .ad r -- adjust right margin only (flush right)
  44   .ad c -- center text on line
  45   .ad b -- adjust both margins (alias: .ad n)
  46   .na   -- temporarily disable adjustment without changing the mode
  47   .ad   -- re-enable adjustment without changing the mode
  48   Adjustment mode is ignored while in no-fill mode (.nf).
  49   loc ***  exist ***  algo **  size **  imp **  (parser reorg would help)
  50
  51 - .fc (field control)
  52   found by naddy@ in xloadimage(1)
  53   loc **  exist ***  algo *  size *  imp *
  54
  55 - .ns (no-space mode) occurs in xine-config(1)
  56   when implementing this, also let .TH set it
  57   reported by brad@  Sat, 15 Jan 2011 15:45:23 -0500
  58   loc ***  exist ***  algo ***  size **  imp *
  59
  60 - \w'' improve width measurements
  61   would not be very useful without an expression parser, see below
  62   needed for Tcl_NewStringObj(3) via wiz@  Wed, 5 Mar 2014 22:27:43 +0100
  63   loc **  exist ***  algo ***  size *  imp ***
  64
  65 --- missing mdoc features ----------------------------------------------
  66
  67 - .Bl -column .Xo support is missing
  68   ultimate goal:
  69   restore .Xr and .Dv to
  70   lib/libc/compat-43/sigvec.3
  71   lib/libc/gen/signal.3
  72   lib/libc/sys/sigaction.2
  73   loc *  exist ***  algo ***  size *  imp **
  74
  75 - edge case: decide how to deal with blk_full bad nesting, e.g.
  76   .Sh .Nm .Bk .Nm .Ek .Sh found by jmc@ in ssh-keygen(1)
  77   from jmc@  Wed, 14 Jul 2010 18:10:32 +0100
  78   loc *  exist ***  algo ***  size **  imp **
  79
  80 - .Bd -filled should not be the same as .Bd -ragged, but align both
  81   the left and right margin.  In groff, it is implemented in terms
  82   of .ad b, which we don't have either.  Found in cksum(1).
  83   loc ***  exist ***  algo **  size **  imp **  (parser reorg would help)
  84
  85 - implement blank `Bl -column', such as
  86   .Bl -column
  87   .It foo Ta bar
  88   .El
  89   loc *  exist ***  algo ***  size *  imp *
  90
  91 - explicitly disallow nested `Bl -column', which would clobber internal
  92   flags defined for struct mdoc_macro
  93   loc *  exist *  algo *  size *  imp **
  94
  95 - In .Bl -column .It, the end of the line probably has to be regarded
  96   as an implicit .Ta, if there could be one, see the following mildly
  97   ugly code from login.conf(5):
  98     .Bl -column minpasswordlen program xetcxmotd
  99     .It path Ta path Ta value of Dv _PATH_DEFPATH
 100     .br
 101     Default search path.
 102   reported by Michal Mazurek <akfaew at jasminek dot net>
 103   via jmc@ Thu, 7 Apr 2011 16:00:53 +0059
 104   loc *  exist ***  algo **  size *  imp **
 105
 106 - inside `.Bl -column' phrases, punctuation is handled like normal
 107   text, e.g. `.Bl -column .It Fl x . Ta ...' should give "-x -."
 108
 109 - inside `.Bl -column' phrases, TERMP_IGNDELIM handling by `Pf'
 110   is not safe, e.g. `.Bl -column .It Pf a b .' gives "ab."
 111   but should give "ab ."
 112
 113 - prohibit `Nm' from having non-text HEAD children
 114   (e.g., NetBSD mDNSShared/dns-sd.1)
 115   (mdoc_html.c and mdoc_term.c `Nm' handlers can be slightly simplified)
 116
 117 - support translated section names
 118   e.g. x11/scrotwm scrotwm_es.1:21:2: error: NAME section must be first
 119   that one uses NOMBRE because it is spanish...
 120   deraadt tends to think that section-dependent macro behaviour
 121   is a bad idea in the first place, so this may be irrelevant
 122   loc **  exist **  algo **  size *  imp **
 123
 124 - When there is free text in the SYNOPSIS and that free text contains
 125   the .Nm macro, groff somehow understands to treat the .Nm as an in-line
 126   macro, while mandoc treats it as a block macro and breaks the line.
 127   No idea how the logic for distinguishing in-line and block instances
 128   should be, needs investigation.
 129   uqs@  Thu, 2 Jun 2011 11:03:51 +0200
 130   uqs@  Thu, 2 Jun 2011 11:33:35 +0200
 131   loc *  exist **  algo ***  size *  imp **
 132
 133 --- missing man features -----------------------------------------------
 134
 135 - groff_www(7) .MTO and .URL
 136   These macros were used by the GNU grep(1) man page.
 137   The groff_www(7) manual page itself uses them, too.
 138   We should probably *not* add them to mandoc.
 139   Just mentioning this here to keep track of the abuse.
 140   Laura Morales <lauretas at mail dot com> 20 Apr 2018 07:33:02 +0200
 141   loc **  exist *  algo *  size **  imp *
 142
 143 --- missing tbl features -----------------------------------------------
 144
 145 - vertical centering in cells vertically spanned with ^
 146   pali dot rohar at gmail dot com 16 Jul 2018 13:03:35 +0200
 147   loc *  exist ***  algo ***  size **  imp *
 148
 149 - support mdoc(7) and man(7) macros inside tbl(7) code;
 150   probably requires the parser reorg and letting tbl(7)
 151   use roff_node such that macro sets can mix;
 152   informed by bapt@ that FreeBSD needs this: 3 Jan 2015 23:32:23 +0100
 153   loc ***  exist **  algo ***  size **  imp ***
 154
 155 - look at the POSIX manuals in the books/man-pages-posix port,
 156   they use some unsupported tbl(7) features, mostly macros in tbl(7).
 157   loc *  exist **  algo **  size **  imp ***
 158
 159 - look what Joerg Schilling manual pages use
 160   Thu, 19 Mar 2015 18:31:48 +0100
 161
 162 --- missing eqn features -----------------------------------------------
 163
 164 - In a matrix, break the output line after each matrix line.
 165   Found in the discussion at CDBUG 2015.  Suggested by Avi Weinstock.
 166   This may not be the ideal solution after all: eqn(7) matrices
 167   are lists of columns, so Avi's proposal would show each *column*
 168   on its own *line*, which is likely to cause confusion.
 169   A better solution, but much harder to implement, would be to
 170   actually show the coordinates of column vectors on different
 171   terminal output lines, using the clumnated output facilities
 172   developed for .Bl -tag, .Bl -column, and also used for tbl(7).
 173   loc *  exist *  algo **  size **  imp **
 174
 175 - The "size" keyword is parsed, but ignored by the formatter.
 176   loc *  exist *  algo *  size *  imp *
 177
 178 - The spacing characters `~', `^', and tab are currently ignored,
 179   see User's Guide (Second Edition) page 2 section 4.
 180   loc *  exist *  algo **  size *  imp **
 181
 182 - Mark and lineup are parsed and ignored,
 183   see User's Guide (Second Edition) page 5 section 15.
 184   loc **  exist **  algo **  size **  imp **
 185
 186 - GNU eqn converts some operators to special characters, for example,
 187   input HYPHEN-MINUS becomes output \(mi, unless it is part of a
 188   quoted word.  mandoc(1) only does this when the operator is
 189   surrounded by blanks, not when it is part of an unquoted word.
 190   Also, check whether there are more such cases (e.g., +?).
 191   reported by bentley@  20 Jun 2017 02:04:29 -0600
 192   loc *  exist **  algo **  size *  imp *
 193
 194 - Primes, opprime, and '
 195   bentley@  Thu, 13 Jul 2017 23:14:20 -0600
 196
 197 --- missing misc features ----------------------------------------------
 198
 199 - man -ks 1,8 route; kn@ Jul 13, 2018 orally
 200
 201 - italic correction (\/) in PostScript mode
 202   Werner LEMBERG on groff at gnu dot org  Sun, 10 Nov 2013 12:47:46
 203   loc **  exist **  algo *  size *  imp *
 204
 205 - change the default PAGER to more -Es and use the pager
 206   even for apropos title line output; req by bapt@
 207   loc *  exist *  algo *  size *  imp ***
 208
 209 - clean up escape sequence handling, creating three classes:
 210   (1) fully implemented, or parsed and ignored without loss of content
 211   (2) unimplemented, potentially causing loss of content
 212       or serious mangling of formatting (e.g. \n) -> ERROR
 213       see textproc/mgdiff(1) for nice examples
 214   (3) undefined, just output the character -> perhaps WARNING
 215   loc ***  exist **  algo **  size **  imp *** (parser reorg helps)
 216
 217 - kettenis wants base roff, ms, and me  Fri, 1 Jan 2010 22:13:15 +0100 (CET)
 218   loc **  exist **  algo **  size ***  imp *
 219
 220 --- compatibility checks -----------------------------------------------
 221
 222 - is .Bk implemented correctly in modern groff?
 223   sobrado@  Tue, 19 Apr 2011 22:12:55 +0200
 224
 225 - compare output to Heirloom roff, Solaris roff, and
 226   http://repo.or.cz/w/neatroff.git  http://litcave.rudi.ir/
 227
 228 - look at AT&T DWB http://www2.research.att.com/sw/download
 229   Carsten Kunze <carsten dot kunze at arcor dot de> has patches
 230   Mon, 4 Aug 2014 17:01:28 +0200
 231   ported version: https://github.com/n-t-roff/DWB3.3
 232   Carsten Kunze  Wed, 22 Apr 2015 11:21:43 +0200
 233
 234 - look at pages generated from reStructeredText, e.g. devel/mercurial hg(1)
 235   These are a weird mixture of man(7) and custom autogenerated low-level
 236   roff stuff.  Figure out to what extent we can cope.
 237   For details, see http://docutils.sourceforge.net/rst.html
 238   noted by stsp@  Sat, 24 Apr 2010 09:17:55 +0200
 239   reminded by nicm@  Mon, 3 May 2010 09:52:41 +0100
 240
 241 - look at pages generated from ronn(1) github.com/rtomayko/ronn
 242   (based on markdown)
 243
 244 - look at pages generated from Texinfo source by yat2m, e.g. security/gnupg
 245   First impression is not that bad.
 246
 247 - look at pages generated by pandoc; see
 248   https://github.com/jgm/pandoc/blob/master/src/Text/Pandoc/Writers/Man.hs
 249   porting planned by kili@  Thu, 19 Jun 2014 19:46:28 +0200
 250
 251 - check compatibility with Plan9:
 252   http://swtch.com/usr/local/plan9/tmac/tmac.an
 253   http://swtch.com/plan9port/man/man7/man.html
 254   "Anthony J. Bentley" <anthonyjbentley@gmail.com> 28 Dec 2010 21:58:40 -0700
 255
 256 - check compatibility with COHERENT troff:
 257   http://www.nesssoftware.com/home/mwc/source.php
 258
 259 - check compatibility with the man(7) formatter
 260   https://raw.githubusercontent.com/rofl0r/hardcore-utils/master/man.c
 261
 262 - check compatibility with
 263   http://ikiwiki.info/plugins/contrib/mandoc/
 264   https://github.com/schmonz/ikiwiki/compare/mandoc
 265   Amitai Schlair  Mon, 19 May 2014 14:05:53 -0400
 266
 267 - check features of the Slackware man.conf(5) format
 268   Carsten Kunze  Wed, 11 Mar 2015 17:57:24 +0100
 269
 270 ************************************************************************
 271 * formatting issues: ugly output
 272 ************************************************************************
 273
 274 - revisit empty in-line macros
 275   look at the difference between "Em x Em ." and "Sq x Em ."
 276   Carsten Kunze  Fri, 12 Dec 2014 00:15:41 +0100
 277   loc *** exist *** algo *** size * imp **
 278
 279 - a column list with blank `Ta' cells triggers a spurious
 280   start-with-whitespace printing of a newline
 281
 282 - In .Bl -column, .It a<tab>"b<tab>c"
 283   shows the quotes in groff, but not in mandoc
 284   loc * exist *** algo ** size * imp **
 285
 286 - In .Bl -column,
 287   .It Em Authentication<tab>Key Length
 288   ought to render "Key Length" with emphasis, too,
 289   see OpenBSD iked.conf(5).
 290   reported again Nicolas Joly via wiz@ Wed, 12 Oct 2011 00:20:00 +0200
 291   loc *  exist ***  algo ***  size **  imp ***
 292
 293 - empty phrases in .Bl column produce too few blanks
 294   try e.g. .Bl -column It Ta Ta
 295   reported by millert Fri, 02 Apr 2010 16:13:46 -0400
 296   loc *  exist ***  algo ***  size *  imp **
 297
 298 - .%T can have trailing punctuation.  Currently, it puts the trailing
 299   punctuation into a trailing MDOC_TEXT element inside its own scope.
 300   That element should rather be outside its scope, such that the
 301   punctuation does not get underlines.  This is not trivial to
 302   implement because .%T then needs some features of in_line_eoln() -
 303   slurp all arguments into one single text element - and one feature
 304   of in_line() - put trailing punctuation out of scope.
 305   Found in mount_nfs(8) and exports(5), search for "Appendix".
 306   loc **  exist **  algo ***  size *  imp **
 307
 308 - Trailing punctuation after .%T triggers EOS spacing, at least
 309   outside .Rs (eek!).  Simply setting ARGSFL_DELIM for .%T is not
 310   the right solution, it sends mandoc into an endless loop.
 311   reported by Nicolas Joly  Sat, 17 Nov 2012 11:49:54 +0100
 312   loc *  exist **  algo **  size *  imp **
 313
 314 - global variables in the SYNOPSIS of section 3 pages
 315   .Vt vs .Vt/.Va vs .Ft/.Va vs .Ft/.Fa ...
 316   from kristaps@  Tue, 08 Jun 2010 11:13:32 +0200
 317
 318 - implicit whitespace around inline equations
 319   example code:  where '$times$' denotes matrix multiplication
 320   must not have an HTML line break, nor a blank, before <math>
 321   partial solution: html.c {"math", HTML_NLINSIDE | HTML_INDENT},
 322   bentley@  Thu, 13 Jul 2017 19:00:59 -0600
 323
 324 - in enclosures, mandoc sometimes fancies a bogus end of sentence
 325   reminded by jmc@  Thu, 23 Sep 2010 18:13:39 +0059
 326   loc *  exist **  algo ***  size *  imp ***
 327
 328 - a line starting with "\fB something" counts as starting with whitespace
 329   and triggers a line break; found in audio/normalize-mp3(1)
 330   This will become easier once escape sequences are represented
 331   by syntax tree nodes.
 332   loc **  exist *  algo **  size *  imp **
 333
 334 - formatting /usr/local/man/man1/latex2man.1 with groff and mandoc
 335   reveals lots of bugs both in groff and mandoc...
 336   reported by bentley@  Wed, 22 May 2013 23:49:30 -0600
 337
 338 --- PostScript and PDF issues ------------------------------------------
 339
 340 - PDF output doesn't use a monospaced font for .Bd -literal
 341   Example: "mandoc -Tpdf afterboot.8 > output.pdf && pdfviewer output.pdf".
 342   Search the text "Routing tables".
 343   Also check what PostScript mode does when fixing this.
 344   reported by juanfra@ Wed, 04 Jun 2014 21:44:58 +0200
 345   instructions from juanfra@  Wed, 11 Jun 2014 02:21:01 +0200
 346     add a new <</Type /Font>> block to the PDF files with /BaseFont /Courier
 347     and change the /Name from /F0 to the new font (/F5 (?)).
 348   re-reported by tb@ Mon, 16 Mar 2015 16:47:21 +0100
 349   loc *  exist **  algo **  size *  imp **
 350
 351 --- HTML issues --------------------------------------------------------
 352
 353 - .Bf at the beginning of a paragraph inserts a bogus 1ex horizontal
 354   space, see for example random(3).  Introduced in
 355   http://mdocml.bsd.lv/cgi-bin/cvsweb/mdoc_html.c.diff?r1=1.91&r2=1.92
 356   reported by deraadt@ Mon, 28 Sep 2015 20:14:13 -0600 (MDT)
 357   loc **  exist **  algo **  size *  imp *
 358
 359 - jsg on icb, Nov 3, 2014:
 360   try to guess Xr in man(7) for hyperlinking
 361   and render them with <a class="Xr" href=...>
 362   https://github.com/Debian/debiman/issues/15
 363   loc *  exist *  algo **  size **  imp **
 364
 365 - The tables used to render the three-part page headers actually force
 366   the width of the <body> to the max-width given for <html>.
 367   Not yet sure how to fix that...
 368   Observed by an Anonymous Coward on undeadly.org:
 369   http://undeadly.org/cgi?action=article&sid=20140925064244&pid=1
 370   loc *  exist *  algo **  size *  imp ***
 371
 372 - generate <img> tags in HTML
 373   idea from florian@  Tue, 7 Apr 2015 00:26:28 +0000
 374   may be possible to implement with .Lk img://something.png alt_text
 375
 376 - check https://github.com/trentm/mdocml
 377
 378 ************************************************************************
 379 * formatting issues: gratuitous differences
 380 ************************************************************************
 381
 382 - .Fn reopens a new scope after punctuation in mandoc,
 383   but closes its scope for good in groff.
 384   Do we want to change mandoc or groff?
 385   Steffen Nurpmeso  Sat, 08 Nov 2014 13:34:59 +0100
 386   loc *  exist **  algo **  size *  imp **
 387
 388 - In .Bl -enum -width 0n, groff continues one the same line after
 389   the number, mandoc breaks the line.
 390   mail to kristaps@  Mon, 20 Jul 2009 02:21:39 +0200
 391   loc *  exist **  algo **  size *  imp **
 392
 393 - .Pp between two .It in .Bl -column should produce one,
 394   not two blank lines, see e.g. login.conf(5).
 395   reported by jmc@  Sun, 17 Apr 2011 14:04:58 +0059
 396   reported again by sthen@  Wed, 18 Jan 2012 02:09:39 +0000 (UTC)
 397   loc *  exist ***  algo **  size *  imp **
 398
 399 - If the *first* line after .It is .Pp, break the line right after
 400   the tag, do not pad with space characters before breaking.
 401   See the description of the a, c, and i commands in sed(1).
 402   loc *  exist **  algo **  size *  imp **
 403
 404 - If the first line after .It is .D1, do not assert a blank line
 405   in between, see for example tmux(1).
 406   reported by nicm@  13 Jan 2011 00:18:57 +0000
 407   loc *  exist **  algo **  size *  imp **
 408
 409 - Trailing punctuation after .It should trigger EOS spacing.
 410   reported by Nicolas Joly  Sat, 17 Nov 2012 11:49:54 +0100
 411   Probably, this should be fixed somewhere in termp_it_pre(), not sure.
 412   loc *  exist **  algo **  size *  imp **
 413
 414 - When the -width string contains macros, the macros must be rendered
 415   before measuring the width, for example
 416     .Bl -tag -width ".Dv message"
 417   in magic(5), located in src/usr.bin/file, is the same
 418   as -width 7n, not -width 11n.
 419   The same applies to .Bl -column column widths;
 420   reported again by Nicolas Joly Thu, 1 Mar 2012 13:41:26 +0100 via wiz@ 5 Mar
 421   reported again by Franco Fichtner Fri, 27 Sep 2013 21:02:28 +0200
 422   reported again by Bruce Evans Fri, 17 Feb 2017 21:22:44 +0100 via bapt@
 423   loc ***  exist ***  algo ***  size **  imp ***
 424   An easy partial fix would be to just skip the first word if it starts
 425   with a dot, including any following white space, when measuring.
 426   loc *  exist *  algo *  size *  imp ***
 427
 428 - The \& zero-width character counts as output.
 429   That is, when it is alone on a line between two .Pp,
 430   we want three blank lines, not two as in mandoc.
 431   loc **  exist **  algo **  size *  imp **
 432
 433 - Sequences of multiple man(7) paragraphs (.PP, .IP) interspersed
 434   with .ps and .nf/.fi produce execessive blank lines, see libJudy
 435   and graphics/dcmtk.  The parser reorg may help with this.
 436
 437 - trailing whitespace must be ignored even when followed by a font escape,
 438   see for example
 439     makes
 440     \fBdig \fR
 441     operate in batch mode
 442   in dig(1).
 443   loc **  exist **  algo **  size *  imp **
 444
 445 ************************************************************************
 446 * warning issues
 447 ************************************************************************
 448
 449 - When a man(1) command returns no result and there was an -S
 450   argument, check the -S argument against the list of valid
 451   architectures and say "Unknown architecture AAA" rather than
 452   "No entry for NNN in the manual" if there is no match.
 453   Requires moving the lists of valid architectures out of
 454   mdoc_validate.c such that they can be used by main.c.
 455   Discussed with jmc@ 10 Aug 2018 19:20:12 +0100.
 456   loc **  exist *  algo *  size *  imp **
 457
 458 - warn about duplicate .Sh/.Ss heads
 459   gre(4): Rename duplicate sections 20 Apr 2018 15:27:33 +0200
 460   loc *  exist *  algo *  size *  imp **
 461
 462 - style message about macros inside .Bd -literal and .Dl, in particular
 463   font changing macros like .Cm, .Ar, .Fa (from the mdoclint TODO)
 464
 465 - style message about mismatches between the section number in the
 466   file name (if it is known) and the section number in .Dt
 467   (from the mdoclint TODO)
 468
 469 - style message about NULL without .Dv (from the mdoclint TODO)
 470
 471 - style message about error constants without .Er (from the mdoclint TODO)
 472
 473 - warn when .Sh or .Ss contain other macros
 474   Steffen Nurpmeso, savannah.gnu.org/bugs/index.php?45034
 475   loc *  exist *  algo *  size *  imp **
 476
 477 - style message about violations of the convention
 478   .An name Aq Mt localpart@domain in AUTHORS (from the mdoclint TODO)
 479
 480 - warn about attempts to call non-callable macros
 481   Steffen Nurpmeso  Tue, 11 Nov 2014 22:55:16 +0100
 482   Note that formatting is inconsistent in groff.
 483   .Fn Po prints "Po()", .Ar Sh prints "file ..." and no "Sh".
 484   Relatively hard because the relevant code is scattered
 485   all over mdoc_macro.c and all subtly different.
 486   loc **  exist **  algo **  size **  imp **
 487
 488 - warn about punctuation - e.g. ',' and ';' - at the beginning
 489   of a text line, if it is likely intended to follow the preceding
 490   output without intervening whitespace, in particular after a
 491   macro line (from the mdoclint TODO)
 492
 493 - makewhatis -p complains about language subdirectories:
 494   /usr/local/man//ru: Unknown directory part
 495
 496
 497 ************************************************************************
 498 * documentation issues
 499 ************************************************************************
 500
 501 - mark macros as: page structure domain, manual domain, general text domain
 502   is this useful?
 503
 504 - mention /usr/share/misc/mdoc.template in mdoc(7)?
 505
 506 - Is all the content from http://www.std.com/obi/BSD/doc/usd/28.tbl/tbl
 507   covered in tbl(7)?
 508
 509 ************************************************************************
 510 * performance issues
 511 ************************************************************************
 512
 513 - the PDF file is HUGE: this can be reduced by using relative offsets
 514
 515 ************************************************************************
 516 * structural issues
 517 ************************************************************************
 518
 519 - POSIX says in the documentation of sysconf(3) that PATH_MAX
 520   is allowed to be so large that it is a bad idea to use it
 521   for sizing static buffers.  So use dynamic buffers throughout.
 522   See the file test-PATH_MAX.c for details.
 523   Found by Aaron M. Ucko in the GNU Hurd via Bdale Garbee,
 524   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=829624
 525
 526 - Is it possible to further simplify ENDBODY_SPACE?
 527
 528 - Find better ways to prevent endless loops
 529   in roff(7) macro and string expansion.
 530
 531 - make buffers for parsing functions const
 532   christos@ via wiz@  Fri, 18 Dec 2015 17:10:01 +0100
 533
 534 - struct mparse refactoring
 535   Steffen Nurpmeso  Thu, 04 Sep 2014 12:50:00 +0200
 536
 537 ************************************************************************
 538 * CGI issues
 539 ************************************************************************
 540
 541  - Enable HTTP compression by detecting gzip encoding and filtering
 542    output through libz.
 543  - Privilege separation (see OpenSSH).
 544  - Enable caching support via HTTP 304 and If-Modified-Since.
 545
 546 ************************************************************************
 547 * to improve in the groff_mdoc(7) macros
 548 ************************************************************************
 549
 550 - .Cd # arch1, arch2 in section 4 pages:
 551   find better way to indicate multiple architectures, maybe:
 552   allow .Dt vgafb 4 "macppc sparc64"
 553   already shown as "Device Drivers Manual (macppc sparc64)"
 554   for apropos, make that "vgafb(4) - macppc # sparc64" instead of "- all"
 555   groff can be made to show multiple arches, too, but it is
 556   tedious to do the string parsing in roff code...
 557   jmc@ 23 Apr 2018 07:24:52 +0100 [man for vgafb(4)...]
 558   loc **  exist **  algo *  size *  imp ***
 559
 560 - use uname(1) to set doc-default-operating-system at install time
 561   tobimensch  Mon, 1 Dec 2014 00:25:07 +0100
 562
 563 - apostrophe (39), circumflex (94), grave (96), tilde (126)
 564   in manuals: \(aq, \(ha, \`, \(ti
 565   Re: [Groff] ASCII Minus Sign in man Pages.
 566   bentley@ 26 Apr 2017 10:02:06 -0600
 567   Do we need to fix existing manuals?
 568   Do we need to fix the definition of the mdoc(7) language?