Re: groff 1.24.0 released

I was overjoyed to hear about this release. Until I got to this part of the
release notes:

GNU troff no longer accepts C0 controls characters in identifiers. We
> prohibit C0 controls to make the language less tolerant of unreadable input


There's no reason to have done this. You've foisted a needlessly disruptive
change upon users that breaks compatibility with older Groff versions and
other Troff implementations. CSTR-54's section on valid character input is
predictably terse, but it clearly states in §10.1
<https://troff.org/54.pdf#page=21>*Input character translations
<https://troff.org/54.pdf#page=21>* that

Ways of inputting the valid character set were discussed in §2.1. The ASCII
> control characters horizontal tab (§9.1), SOH (§9.1), and backspace (§10.3)
> are discussed elsewhere. The newline delimits input lines. *In addition,
> STX, ETX, ENQ, ACK, and BEL are accepted*, and may be used as delimiters
> or translated into a graphic with tr (§10.5). All others are ignored.


Consider the amount of work that's been put into making Groff
backwards-compatible with historical Troffs (even in this new release). How
does it make sense to support *most* historical Troff macros and syntax,
yet make a selective exception for a feature that, realistically, few Groff
users know about, and even fewer make use of?

Regards,
— John




On Sun, 1 Mar 2026 at 09:50, G. Branden Robinson <
[email protected]> wrote:

> We are pleased to announce the availability of groff 1.24.0.  Obtain
> it from the GNU mirror network,
>
>   https://ftpmirror.gnu.org/groff/groff-1.24.0.tar.gz
>
> or, if the network is for some reason inoperative, directly from GNU.
>
>   https://ftp.gnu.org/gnu/groff/groff-1.24.0.tar.gz
>
> Ensure the integrity of your download by checking this source code
> archive's cryptographic signature; see "Obtaining groff" below.
>
>
> What is groff?
> ==============
>
> groff (GNU roff) is a typesetting system that reads plain text input
> that includes formatting commands to produce output in PostScript,
> PDF, HTML, or DVI formats or for display to a terminal.  Formatting
> commands can be low-level typesetting primitives, macros from a
> supplied package, or user-defined macros.  All three approaches can be
> combined.
>
> A reimplementation and extension of troff and other programs from AT&T
> Unix, groff is widely available on POSIX and other systems owing to its
> long association with Unix manuals, including man pages.  It and its
> predecessor have produced several best-selling software engineering
> texts.  groff can create typographically sophisticated documents while
> consuming minimal system resources.
>
>   https://www.gnu.org/software/groff/
>
>
> Changes
> =======
>
> Since the groff 1.24.0.rc4 release candidate was made available on 20
> February, 2 people have authored a total of 32 commits.
>
> $ git shortlog --summary 1.24.0.rc4..1.24.0
>      1  Deri James
>     31  G. Branden Robinson
>
> Thanks to Alexis Hildebrandt, Bjarni Ingi Gislason, and Deri James for
> reporting defects in rc4.
>
> * A defect in gropdf that caused it to sometimes fail to format the
>   numeral "0" has been fixed, and a regression test for it added.
>
> * A defect in the build scripts' generation of HTML documents with groff
>   (affecting the "pic.html" manual and the "webpage.html" example) has
>   been corrected.
>
> * Spurious test failures on FreeBSD 14.0 and 15.0, NetBSD 10.0, OpenBSD
>   7.8, and macOS/Darwin have been resolved.
>
> See "Details" below for changes since the groff 1.23.0 release.
>
>
> Defects not resolved
> --------------------
>
> * On some systems (CentOS 7.9, Ubuntu 20.04) but not others (Debian
>   12.12, Ubuntu 24.04, Solaris 11, Termux/Android), the test script
>   "tmac/tests/an_UR-works.sh" fails with the following message in its
>   log file.
>
>     I/O Error: Couldn't open file '-'
>
>   We have been unable to locate a cause.  Hypotheses include a version
>   of pdftotext(1) that differs from others more commonly used (there are
>   at least two independent implementations), or the use of AppArmor on
>   Linux.  We'd greatly appreciate your help root-causing this issue.
>
> Highlights of groff 1.24.0
> --------------------------
>
> *  groff_man(7) and groff_mdoc(7) now support hyperlinks between man
>    pages in PDF.  They use the "man:" scheme for URLs, and can be
>    prepared to use PDF bookmarks internal to the document in a
>    collection of man pages if desired.  groff builds a
>    "groff-man-pages.pdf" file that illustrates.
>
> *  The groff_man(7) extension macros `SY` and `YS` macros have been
>    changed to enable greater user control over vertical spacing and to
>    make them convenient for synopsizing C language functions, not just
>    commands.  In a "Synopsis" section of a man page, existing synopses
>    consisting of a single item require no migration.  This is the most
>    common case.
>
> *  groff 1.24.0 includes version 2.6 of the mom macro package.
>
> *  The groff_mm(7) macro package has been adjusted in dozens of minor
>    ways to clean up its user interface and more accurately reproduce
>    historical mm documents, such as London & Reiser's 1978 paper
>    describing Unix/V32, the Unix port to the VAX-11/780.
>
> *  groff 1.24.0 includes "install-font.bash", an example
>    script to aid integration of third-party fonts with groff.
>
> *  The pic(1) preprocessor supports a new "polygon" command, and extends
>    reference point syntax to permit selection of objects' vertices and
>    midpoints (where applicable).
>
> *  The gropdf(1) output driver has several new features.
>    - JFIF/JPEG and JPEG 2000 image files are embeddable in documents.
>    - If PerlMagick is installed, many more image formats are as well.
>    - It ships a grops(1)-compatible "SS" (slanted symbol) font.
>    - It subsets fonts by default, reducing file size.
>    - Its output conforms to the ISO 32000/PDF 1.7a standard by default.
>    - It permits control of page numbers in a PDF reader's outline pane.
>    - It supports characters outside the Unicode Basic Latin subset
>      in bookmarks, named destinations, and external hyperlinks.
>
> *  The grops(1) output driver now supports fonts encoded using UTF-16.
>
> *  The new "-t" option to the grotty(1) output driver causes it to
>    output ECMA SGR 38 and 48 escape sequences, which permit
>    specification of character cell foreground and background colors in
>    the RGB color space with 8 bits per channel.
>
> *  GNU troff's new `hydefault` request permits a distinct hyphenation
>    mode default to be configured for each environment.  groff's
>    localization macro files configure an appropriate default for the
>    selected language.
>
> *  The formatter, GNU troff, has many new features to aid debugging
>    of documents and macro files.  All write to the standard error
>    stream.  `pchar`, `pcolor`, `pcomposite`, `pfp`, `pftr`, and `phw`
>    report the state of data manipulated by requests of the same name
>    without the "p" prefix.  `ptr` has been renamed to `pwh` accordingly.
>    `pm` now dumps, in JSON encoding, the contents of macros, strings,
>    and diversions named as arguments.  `pline` does the same for a
>    pending output line.  `pstream` reports the status of open file
>    streams.  `pnr` accepts register names as arguments, reporting only
>    those requested, and now discloses the autoincrementation amount and
>    interpolation format of each register (if it is not string-valued).
>
> *  GNU troff now implements saturating rather than wrapping integer
>    arithmetic.
>
> *  GNU troff now implements a more regular request syntax.  The requests
>    `cf`, `hpf`, hpfa`, `lf`, `mso`, msoquiet`, `ns`, pi`, `pso`, `so`,
>    `soquiet`, `sy`, and `trf` now handle their arguments as the string-
>    populating requests `ds` and `as` do, stripping a leading neutral
>    double quote from relevant arguments and thereby permitting leading
>    spaces to be embedded in them.  A consequence is that GNU troff
>    requests now handle file names with spaces in them as easily as any
>    other file name, unlike other troffs.
>
> *  The soelim(1) preprocessor interprets `.so` tokens compatibly with
>    the foregoing change to GNU troff(1).
>
> *  groff now offers output localization for Polish, Russian, and
>    Spanish, including hyphenation patterns and macro package string
>    translations.
>
> *  A new macro file "koi8-r.tmac" supports the KOI8-R character
>    encoding, which in turn supports the new Russian locale for groff.
>
> For a more comprehensive list of feature changes, see "News" below.
>
> Much attention has been given to fixing bugs, validating input,
> improving diagnostic messages, and correcting and expanding
> documentation.  The previous release shipped with 164 automated tests;
> this one ships with over 300.
>
> Details
> -------
>
> Since groff 1.23.0 was released on 5 July 2023, 30 people have authored
> a total of over 5,200 commits.  (One author appears under two IDs.)
>
> $ git shortlog --summary 1.23.0..1.24.0
>     14  Alejandro Colomar
>      2  Alexis
>      6  Alexis Hildebrandt
>      4  Bjarni Ingi Gislason
>      3  Bruno Haible
>      5  Colin Watson
>      1  Collin Funk
>      2  Dariusz Chilimoniuk
>     12  Dave Kemper
>      1  Deri
>     83  Deri James
>      1  Douglas McIlroy
>      4  Duncan Losin
>      1  Eloi Montañés
>   5159  G. Branden Robinson
>      1  Helmut Grohne
>      2  Ian Ropers
>      3  Ingo Schwarze
>      1  Keith Marshall
>      4  Lennart Jablonka
>      4  Lukas Javorsky
>      1  Nikita Ivanov
>     10  Norwid Behrnd
>      2  Paul Eggert
>     44  Peter Schaffter
>      1  Pim
>      1  Robert Yang
>      1  Sebastien Peterson-Boudreau
>      3  Sven Schober
>      6  TANAKA Takuji
>      1  onf
>
> For a list of feature changes, see "News" below.
>
> As of this writing, per the GNU Savannah bug tracker, the groff
> project has resolved 378 issues as fixed for the 1.24.0 release.
>
> Classifying these issues by type and the component of the project to
> which they apply, we find the following.
>
>   Type                              Component
>   ----                              ---------
>   Build/installation           36   Core                          122
>   Crash/unresponsive            8   Driver: grohtml                 1
>   Documentation                58   Driver: gropdf                 29
>   Feature change               61   Driver: grops                   3
>   Incorrect behavior          115   Driver: grotty                  5
>   Lint                         14   Driver: others/general          5
>   Rendering/cosmetics          25   Font: devpdf                    9
>   Test                          8   Font: devps                     1
>   Warning/suspicious behavior  53   Font: others/general            1
>                                     General                        41
>                                     Macros: man                    19
>                                     Macros: mdoc                   15
>                                     Macros: me                      4
>                                     Macros: mm                     33
>                                     Macros: mom                     9
>                                     Macros: ms                      9
>                                     Macros: others/general         29
>                                     Preprocessor: eqn               4
>                                     Preprocessor: grn               0
>                                     Preprocessor: html              2
>                                     Preprocessor: pic              10
>                                     Preprocessor: preconv           0
>                                     Preprocessor: refer             4
>                                     Preprocessor: soelim            1
>                                     Preprocessor: tbl               8
>                                     Preprocessor: others/general    6
>                                     Utilities                       8
>
> Another way of capturing the amount of revision is as follows.
>
> $ git diff --stat 1.23.0 1.24.0 | tail -n 1
>  1224 files changed, 157612 insertions(+), 83697 deletions(-)
>
>
> Obtaining groff
> ===============
>
> Here are the compressed sources and a GPG detached signature[*].
>   https://ftp.gnu.org/gnu/groff/groff-1.24.0.tar.gz
>   https://ftp.gnu.org/gnu/groff/groff-1.24.0.tar.gz.sig
>
> Use a mirror for higher download bandwidth.
>   https://ftpmirror.gnu.org/gnu/groff/groff-1.24.0.tar.gz
>   https://ftpmirror.gnu.org/gnu/groff/groff-1.24.0.tar.gz.sig
>
> Here are the SHA-1 and SHA-256 checksums.
>
> d0d5e822467695e158769c29988a89f2ce67e194  groff-1.24.0.tar.gz
> 55u82P8+0CAOesVdOWKhXhGMEimZAhMCXy/IsmRydXA=  groff-1.24.0.tar.gz
>
> The SHA-256 checksum is encoded in Base64 instead of the hexadecimal
> form that most checksum tools default to.  The mechanism follows.
>
> sha256sum < groff-1.24.0.tar.gz | cut -f1 -d\  | xxd -r -p | base64
>
> (Because "base64" reads from a pipe, it doesn't know the file name, and
> so the file name will not appear in the output.)
>
> [*] Use a .sig file to verify that the corresponding file (without the
>     .sig suffix) is intact.  First, be sure to download both the .sig
>     file and the corresponding archive.  Then, verify the archive.
>
>       gpg --verify groff-1.24.0.tar.gz{.sig,}
>
>     If that command fails because you don't have the required public
>     key, you can import it.
>
>       wget -O 108747.asc \
>         'https://savannah.gnu.org/people/viewgpg.php?user_id=108747'
>       gpg --import 108747.asc
>
>     Re-run the 'gpg --verify' command subsequently.
>
>
> Caveats
> =======
>
> *  GNU tools, or otherwise POSIX-conforming ones, are generally required
>    to build on Solaris 10 or 11.  See the "PROBLEMS" file in the
>    distribution archive.
>
> *  Solaris 10 has known problems with automated tests; see the
>    "PROBLEMS" file in the distribution archive.
>
>
> News
> ====
>
> Noteworthy incompatible changes
> -------------------------------
>
> *  If your roff(7) documents follow any of the requests `cf`, `hpf`,
>    `hpfa`, `mso`, `msoquiet`, `nx`, `open`, `opena`, `so`, `soquiet`, or
>    `trf` with a comment after their file name argument, and did not
>    place that comment immediately after the file name, you are likely to
>    get a diagnostic message resembling the following.
>
>     warning: cannot open macro file 'e.tmac ': No such file or directory
>
>    Or, less likely, the formatter will open the wrong file, one with
>    spaces at the end of its name.  That is because these requests are
>    now able to process file names containing space characters.  (This
>    change also makes the request syntax consistent with that of `ds`,
>    `as`, and others.)  A quick fix is to place the comment escape
>    sequence as early as possible.  For example, we would change:
>
>      .mso e.tmac \" Load Eric Allman's package.
>
>    to:
>
>      .mso e.tmac\" Load Eric Allman's package.
>
>    to tell the formatter to load the "e.tmac" file rather than
>    "e.tmac ".  See the items below for further details.
>
> *  If your roff(7) documents specify a file name that starts with a
>    neutral double quote (") to any of the requests `cf`, `hpf`,
>    `hpfa`, `mso`, `msoquiet`, `nx`, `open`, `opena`, `so`, `soquiet`, or
>    `trf`, you are likely to get a diagnostic message, or the formatter
>    will open a file of the same name except for the leading neutral
>    double quote.  That is because these requests are now able to process
>    file names containing leading space characters.  (This change also
>    makes the request syntax consistent with that of `ds`, `as`, and
>    others.)  The solution is to add an additional neutral double quote
>    to the start of the file name argument.  For example, we would
>    change:
>
>      .so "5150".lrc
>
>    to:
>
>      .so ""5150".lrc
>
>    to tell the formatter to read a file named '"5150".lrc', where the
>    neutral single quotes bracket the file name.
>
> *  groff mdoc(7)'s font customization feature, undocumented but
>    analogous to that of 4.4BSD mdoc, now expects the strings that
>    designate font names to be precisely that: font _names_ (or abstract
>    styles, or mounting positions), rather than arbitrary *roff syntax.
>    (String interpolations remain acceptable, as long as what they
>    interpolate is a valid argument to the `ft` request or `\f[xxx]`
>    escape sequence.)
>
> *  Support for terminal devices using the CCSID 1047 (EBCDIC) encoding
>    has been withdrawn.  See below for motivation and a workaround.
>
> troff
> -----
>
> *  troff now recognizes an -S option, which "locks" safer mode,
>    rejecting any subsequent specification of -U on the command line with
>    an error diagnostic.
>
> *  The `cf` request is now disabled in safer mode; as with `pi` and
>    `sy`, you must specify troff's "unsafe mode" option `-U` to use it.
>    Alternatively, use the `trf` request, available since groff 0.6
>    (circa 1990), to embed a file in GNU troff's output while discarding
>    characters (most C0 and C1 controls) that are invalid as GNU troff
>    input--and incidentally also undefined in GNU troff output.
>
> *  The `hpfcode` request now emits an error when used, advising of its
>    planned withdrawal, but then proceeds with normal behavior.  The
>    documented replacement mechanism, the `hcode` request, has existed
>    since groff 1.02 (June 1991) at the latest.
>
> *  The `mso` request no longer attempts to open a macro file named, say,
>    "tmac.s" if "s.tmac" was specified as the argument and not found, nor
>    vice versa.  This feature was a convenience for some old AT&T troff
>    installations, but few of those remain in the field, and of those
>    that we know to survive, few use a macro file naming convention for
>    which this feature is any help.  (DWB 3.3 and Solaris do not, and we
>    think other System V troffs don't, either.  Only Plan 9 troff does.)
>    `mso` now simply processes the macro search path for a file name
>    matching the request argument, and succeeds or fails depending on an
>    exact match.
>
>    If you desire this functionality for portability (keeping in mind
>    that `mso` is itself a groff extension), consider the following.
>
>      .\" Load the ms package, whatever it might be named.
>      .\" troffs without groff extensions must know its full path.
>      .if !\n(.g .so /path/to/tmac.s
>      .\" The following requests do nothing on non-GNU troffs.
>      .do msoquiet s.tmac\" If file present, defines `LP` macro.
>      .do if !d LP .msoquiet tmac.s
>
> *  GNU troff no longer accepts nonpositive page lengths.  Attempting to
>    set one with the `pl` request clamps the page length to the vertical
>    motion quantum as `ll` does with the horizontal motion quantum in
>    AT&T and GNU troffs.
>
> *  GNU troff no longer accepts a newline as a delimiter for the
>    parameterized escape sequences `\A`, `\b`, `\o`, `\w`, `\X`, and
>    `\Z`.
>
> *  GNU troff no longer accepts C0 controls or Latin-1 Supplement
>    characters in identifiers.  We prohibit C0 controls to make the
>    language less tolerant of unreadable input, and Latin-1 Supplement
>    code points to enable us to pivot to reading UTF-8-encoded input in a
>    future release.  (Thus, we plan for Latin-1 Supplement characters to
>    again be accepted in identifiers, but only as components of multibyte
>    UTF-8 sequences.)
>
> *  The `color`, `cp`, `kern`, `linetabs`, and `vpt` requests now
>    interpret arguments with negative values as instructions to disable
>    the corresponding feature, using the *roff integer-to-Boolean
>    conversion idiom instead of the C/C++ one.  Thus, if you invoke these
>    requests with a register interpolation as an argument, the outcome
>    agrees with an `if` test of the register's value.
>
> *  GNU troff now implements saturating rather than wrapping integer
>    arithmetic.  Where before overflow would cause an error diagnostic
>    and abort evaluation of the expression, the formatter now emits a
>    warning diagnostic in the "range" category and continues evaluation.
>
> *  GNU troff now strips a leading neutral double quote from the argument
>    to the `cf`, `hpf`, `hpfa`, `lf`, `mso`, `msoquiet`, `nx`, `pi`,
>    `pso`, `so`, `soquiet`, `sy`, and `trf` requests, and the second
>    argument to the `open` and `opena` requests, allowing it to contain
>    embedded leading spaces.
>
> *  GNU troff now accepts space characters in the argument to the `cf`,
>    `hpf`, `hpfa`, `lf`, `mso`, `msoquiet`, `nx`, `so`, `soquiet`, and
>    `trf` requests, and the second argument to the `open` and `opena`
>    requests.  See "soelim" below.
>
> *  The foregoing two changes make the syntax of the listed requests
>    consistent with that of `ds`, `as`, and others that take arguments
>    that the formatter reads to the next newline.
>
> *  The "number" warning category has been withdrawn.  The diagnostic
>    that formerly used it has been promoted to an error.
>
> *  The "el" warning category has been withdrawn.  If enabled (which it
>    was not by default), the formatter would emit a diagnostic if it
>    inferred an imbalance between `ie` and `el` requests.  Unfortunately
>    its technique wasn't reliable and sometimes spuriously issued these
>    warnings, and making it perfectly reliable did not look tractable.
>    We recommend using brace escape sequences `\{` and `\}` to ensure
>    that your control flow structures remain maintainable.
>
> *  The "right-brace" warning category has been withdrawn.  If enabled
>    (which it was not by default), the formatter would emit a diagnostic
>    in exactly one circumstance: when a numeric expression was expected
>    (as, for instance, the second argument to an `nr` request) but a
>    right brace escape sequence `\}` was encountered instead.  This
>    diagnostic still issues, but it is now an error.
>
> *  GNU troff now performs some limited processing/transformation of the
>    argument to the `\X` escape sequence and its counterpart `device`
>    request, to address the requirement that some documents have to pass
>    metadata that must encode non-ASCII characters in device extension
>    commands.  (For example, a document author may desire a document's
>    section headings containing non-ASCII code points to appear correctly
>    in PDF bookmarks.  Further, GNU troff encodes its output page
>    description language only in ASCII.)  This change is expected to be
>    of significance mainly to developers of output drivers for groff;
>    groff_diff(7) describes the transformations.  If you have been using
>    `\X` or `.device` to pass ASCII data to the output driver as a device
>    extension command and require that it remain precisely as-is, use the
>    `\!` escape sequence or `output` request, and prefix your data with
>    "x X ", the device-independent troff means of expressing a device
>    extension command (see groff_out(5)).
>
> *  In nroff mode (in other words, when producing output for devices that
>    claim to be terminals), the formatter now reports warning diagnostics
>    regarding certain output problems using units of lines (vertically)
>    and character cells [ens] (horizontally) instead of inches (or the
>    unit configured with the `warnscale` request) to describe the drawing
>    position where the problem occurred.
>
> *  The device-independent page description language produced by GNU
>    troff now reports unbreakable spaces (those produced with the `\~`
>    escape sequence) as word boundaries with the documentary 'w' command,
>    just as it does for regular breakable spaces.
>
> *  A new request, `hydefault`, and read-only register, `.hydefault`,
>    manage the default automatic hyphenation mode of an environment.
>    This resolves a long-standing problem of *roff formatting.
>
>      When processing input like this,
>      .nh
>      and we temporarily shut off automatic hyphenation,
>      .hy
>      the foregoing request would not do exactly what we expect.
>
>    AT&T and other troffs apply a hyphenation mode of 1 to the final
>    input line (and subsequent ones), rather than restoring the mode in
>    use before the `nh` request.  Apart from overturning user
>    expectations, for GNU troff "1" is not an appropriate mode for its
>    English hyphenation patterns.  (For example, "alibi" would break as
>    "ali-bi" instead of "al-ibi" after this argumentless `hy`
>    invocation.)  With updates to groff's localization files accompanying
>    this release, the foregoing input now works as desired.
>
> *  A new read-only, string-valued register, `.trap`, interpolates the
>    name of the next page location trap after the drawing position.
>
> *  New registers `.it`, `.itc`, and `.itm` are available.  These
>    read-only (and, in the case of `.itm`, string-valued) registers
>    report the number of lines remaining in a pending input trap, a
>    Boolean indication of whether that pending input trap honors output
>    line continuation (cf. the `it` and `itc` requests), and the name of
>    the macro associated with the pending input trap, respectively.
>
> *  A new request, `pchar`, reports to the standard error stream details
>    of any class or ordinary, special, or indexed character arguments.
>
> *  A new request, `pcolor`, reports to the standard error stream details
>    of each color name specified as an argument, including its color
>    space identifier and channel value assignments.  Without arguments,
>    all defined colors are listed.  (A device's default stroke and/or
>    fill colors, "default", are not listed since they are immutable and
>    their details unknown to the formatter.)
>
> *  A new request, `pcomposite`, reports to the standard error stream the
>    list of configured composite character mappings.
>
> *  A new request, `pfp`, reports to the standard error stream the
>    list of occupied font mounting positions and the corresponding
>    abstract style name or font information.
>
> *  A new request, `pftr`, reports to the standard error stream the
>    list of configured font translations.
>
> *  A new request, `phw`, reports to the standard error stream the
>    list of hyphenation exceptions associated with the current
>    hyphenation language.
>
> *  A new request, `pline`, reports to the standard error stream the list
>    of output nodes (an internal data structure) corresponding to the
>    pending output line.  The list is empty if no such nodes exist.
>
> *  The `pm` request now interprets any arguments as a sequence of macro,
>    string, or diversion names, and reports their contents.
>
> *  The `pnr` request now additionally reports the autoincrementation
>    amount and interpolation format of each register (if it is not
>    string-valued).
>
> *  The `pnr` request now accepts arguments.  It treats each as
>    identifying a register and reports its properties to the standard
>    error stream.
>
> *  A new request, `pstream`, reports to the standard error stream the
>    name of each stream opened with the `open` or `opena` requests, the
>    name of the file backing it, and its mode (writing or appending).
>
> *  The `ptr` request has been renamed to `pwh` (mnemonic: "Print WHen
>    traps will spring").  As a rule, debugging requests starting with `p`
>    correspond to a request name that manipulates the objects reported on
>    when the `p` is removed.  However, `ptr` had nothing to do with the
>    `tr` request.  The only exceptions to the stated rule of `p`-removal
>    are now `line`, `m`, and `stream`, none of which are request names.
>
> *  The `hla` request, when invoked with no arguments, now clears the
>    hyphenation language, disabling automatic hyphenation.
>
> *  The read-only registers `.m` and `.M` now interpolate "default" when
>    the default color is selected as the stroke or fill color,
>    respectively, rather than interpolating nothing.
>
> *  Numeric expression contexts that accept the `z` and `u` scaling
>    units, such as the `ps` request and `\s` escape sequence, now also
>    accept `p` and `s`.
>
> *  troff's `-c` command-line option now also removes the `color`
>    request's ability to enable multi-color output.
>
> eqn
> ---
>
> *  The "gifont" primitive replaces "gfont" as the means of configuring
>    the global italic face in preprocessed equations.  "gfont" remains
>    recognized as a synonym for backward compatibility.  The new name is
>    intended to ease acquisition of the eqn language in light of GNU
>    eqn's thirty-year-old extensions "gbfont" and "grfont".
>
> *  New parameters tunable with the GNU eqn "set" primitive, "half_space"
>    and "full_space", enable a document to configure the space widths
>    produced by the eqn tokens '^' and '~', respectively.  Previously,
>    their widths were determined by the "thin_space" and "thick_space"
>    parameters used to tune GNU eqn's automatic spacing computations.
>
> *  The new "reset" primitive restores a named parameter to its default.
>
> groff
> -----
>
> *  The groff command now encodes the fate of failing processes in the
>    pipeline it constructs and runs so that this information cannot be
>    confused with groff's own error conditions (such as a usage error,
>    which now produces an exit status of 2).  See the section "Exit
>    status" of groff(1) for details.
>
> *  groff now passes the -S option to pic and troff if it is specified.
>
> nroff
> -----
>
> *  nroff now recognizes the -a, -D, -I, and -Z options and passes them
>    to groff.
>
> *  nroff now supports clustered options ("-tzms", for example) as groff,
>    troff, and other GNU getopt-using programs do.
>
> pic
> ---
>
> *  A new command, `polygon`, supports drawing polygons using arbitrary
>    vertices.  The command furthermore accepts the `fill[ed]` modifier.
>    You can address a polygon's vertices and the midpoints of its edges
>    with the new `.v[er[tex]]` and `.mid[point]` syntax suffixed to an
>    object identifier, analogously to the existing compass point and
>    `.c[enter]` feature.  Thanks to Duncan Losin.
>
> *  pic's -S option now "locks" safer mode, rejecting any subsequent
>    specification of -U on the command line with an error diagnostic.
>
> soelim
> ------
>
> *  soelim no longer requires embedded space characters in `so` arguments
>    to be backslash-escaped.  (It continues to support that syntax, even
>    though neither the AT&T nor GNU troff formatters ever have.)  You can
>    now embed a sequence of leading spaces in the argument by prefixing
>    it with a with a neutral double quote character ("), which the
>    program discards.  These changes are to better align this program's
>    parsing rules with the language of the formatter; consider the `ds`
>    and `as` requests.
>
> Macro packages
> --------------
>
> *  Keith Marshall's pdfmark package is no longer distributed with groff,
>    but is now separately maintained.  Please visit
>    <https://savannah.nongnu.org/projects/groff-pdfmark> for the latest
>    version.
>
> *  mom version 2.6 is distributed with this release.  It supports
>    multi-line headings.  Thanks to Peter Schaffter.
>
> *  The device-specific macro files loaded by "troffrc" automatically on
>    startup, such as "html.tmac", no longer perform font translations for
>    some font names used by varieties of AT&T troff ('C', 'Hb', 'HX', and
>    several others).
>
>    These names are not portable: in AT&T troff, the font repertoire,
>    like the special character repertoire, was device-dependent.  Since
>    groff 1.23.0, GNU troff diagnoses attempts to use nonexistent font
>    names.  We recommend addressing such portability issues wherever
>    suits you: (1) in a document, perhaps by using `ie` and `el` requests
>    and the `.g` register to test whether the formatter claims support
>    for groff extensions, then `ie` and `el` again with the `F` groff
>    conditional expression operator to check for font availability, and
>    to perform font remappings with the groff `ftr` request as desired;
>    (2) doing so in your "troffrc" file; or (3) by modifying these macro
>    files similarly.  Users of the "dvi" and "lbp" output devices should
>    be aware that these devices don't supply full families of monospaced
>    fonts (and never have).  See grodvi(1) and grolbp(1) for lists of
>    font names supported by each device.
>
>    The legacy names are retained for the "pdf" and "ps" devices for this
>    release; however, use of them prompts one warning in the "font"
>    category from the formatter per deprecated name.  We expect to
>    withdraw support for the names completely in a future groff release.
>    See gropdf(1) and grops(1) for lists of font names supported by each
>    device.
>
> *  Hyperlink support is now enabled by default on PDF and terminal
>    devices for an (man) and doc (mdoc) documents.  Instructions and
>    commented code for disabling it are in the "man.local" and
>    "mdoc.local" files.
>
> *  The `PDFPIC` macro implemented in the "pdfpic.tmac" macro file now
>    uses identify(1) (from ImageMagick/GraphicsMagick) and file(1), if
>    available, to attempt to determine the dimensions of an image to be
>    embedded in a PDF document.  See also the item regarding gropdf(1)
>    below.  Thanks to Deri James.
>
> *  The an (man) package now supports use of its hyperlink macros (`UR`,
>    `UE`, `MT`, and `ME`) in paragraph tags (that is, on the next line
>    after a `TP` macro call).  Use of the `MR` man page cross reference
>    macro in a tag was already supported in groff 1.23.0.
>
> *  The behavior of the an (man) package's `SY` and `YS` macros has been
>    expanded to enable greater user control over vertical spacing and to
>    make them convenient for synopsizing C language functions, not just
>    commands.  `SY` no longer puts vertical space on the output, and
>    initially breaks the output line _only_ if it is encountered
>    repeatedly without a preceding `YS` call.  The computed indentation
>    of synopsis lines after the first now also includes the width of
>    anything already on the output line, so that you can precede the `SY`
>    call with, for instance, the C language data type used for the return
>    value in a function prototype.  The `SY` macro now accepts an
>    optional second argument.  This second argument is typeset in bold,
>    replaces the fixed-width space that is appended to the synopsis
>    keyword in `SY`'s single-argument form, and is used in computation of
>    the indentation of non-initial synopsis lines.  However, this
>    computed indentation can now also be overridden with that of the
>    previous synopsis item.  To do this, give any argument to the `YS`
>    macro call "closing" the synopsis whose indentation you want to
>    reuse.  When you're done with such a grouped synopsis, leave the
>    argument off the final `YS` call.
>
>    In a "Synopsis" section of a man page, existing synopses consisting
>    of a single item require no migration.  This is the most common case.
>
>    For others, where before you would write...
>
>    .SY mv
>    .I source
>    .I destination
>    .YS
>    .
>    .SY mv
>    .I source
>    \&.\|.\|.\&
>    .I destination-directory
>    .YS
>
>    ...you would now write the following.
>
>    .SY mv
>    .I source
>    .I destination
>    .YS
>    .
>    .P
>    .SY mv
>    .I source
>    \&.\|.\|.\&
>    .I destination-directory
>    .YS
>
>    (That is, simply add a paragraphing macro.)
>
>     And where before you would write...
>
>    .SY mv
>    .B \-h
>    .
>    .SY mv
>    .B \-\-help
>    .YS
>
>     ...you would now write the following.
>
>    .SY mv
>    .B \-h
>    .YS
>    .
>    .SY mv
>    .B \-\-help
>    .YS
>
>    (That is, simply add `YS` after the first synopsis item.)
>
>    Likely the biggest benefit of these changes is that it is now much
>    easier to format C function prototypes with these macros.  Here's how
>    we would synopsize a somewhat complex standard C library function.
>
>    .B "#include <stdio.h>"
>    .P
>    .B void *\c
>    .SY bsearch (
>    .BI const\~void\~*\~ key ,
>    .BI const\~void\~*\~ base ,
>    .BI size_t\~ nmemb ,
>    .BI int\~(* compar )\c
>    .B (const\~void\~*, const\~void\~*));
>    .YS
>
> *  The an (man), doc (mdoc), and doc-old (mdoc-old) macro packages have
>    changed the default line length when formatting on terminals from 78n
>    to 80n.  The latter is a vastly more common device configuration, but
>    that line length had been avoided since the groff 1.18 release in
>    July 2002 (prior to that, the line length was 65n, as in AT&T nroff),
>    for an undocumented reason.  That reason appears to have been the
>    interaction of bugs in GNU tbl(1) with an aspect of grotty(1)'s
>    design.  Those bugs have been resolved.  A man(1) program can still
>    instruct groff to format for any desired line length by setting the
>    `LL` register on {g,n,t}roff's command line.
>
> *  The an (man) and doc (mdoc) macro packages use slightly different
>    vertical margins than previously, to align more closely with the
>    traditional implementations of these packages.  Per man(7) in the
>    AT&T Unix System III manual (June 1980), the text area was 6.5 by 10
>    inches (on typesetters).  When formatting for terminals with
>    continuous rendering disabled (by default, it is enabled), the page
>    footer now sets one line higher than before.
>
> *  The an (man) and doc (mdoc) macro packages have added additional
>    registers `BP`, `PO`, and `TS` for user configuration of man page
>    rendering at formatting time.  As noted in groff_man(7) and
>    groff_mdoc(7), documents should never manipulate these.
>
> *  The an (man) and doc (mdoc) macro packages now support a `BP`
>    register to configure the ("base") paragraph inset amount; that is
>    the amount used by man(7) for paragraphs not within an `RS`/`RE`
>    relative inset, and in mdoc(7) for all paragraphs.  Formerly, the
>    `IN` register configured this amount with other indentation and inset
>    amount parameters used by man(7).  (In mdoc(7), it had no other
>    purpose.)  The base paragraph indentation default is now 5n,
>    corresponding to that used by historical man(7) and mdoc(7)
>    implementations going back to Unix Version 7 (1979) and 4.3BSD-Reno
>    (1990), respectively.
>
> *  The an (man) and doc (mdoc) macro packages now support a `PO`
>    register to configure the page offset used by the formatter.
>
> *  The an (man) macro package now supports a `TS` register to configure
>    the minimum space required between the tag of a `TP` paragraph and
>    its body.  (If the width of the tag's formatted text plus this space
>    exceeds the paragraph indentation, the line is broken after the tag.)
>    This parameter, formerly hard-coded as `1n`, now defaults to `2n`.
>
> *  The an (man) macro package's `IP` macro no longer honors the formerly
>    hard-coded 1n tag separation noted in the previous item.  This means
>    that the first argument to the `IP` macro can abut the text of the
>    paragraph with no intervening space.  If you use a word instead of
>    punctuation or a list enumerator for `IP`'s first argument, consider
>    migrating to `TP`.
>
> *  The "an-ext.tmac" macro file, loaded automatically by the an (man)
>    macro package, no longer defines `DS` and `DE` macros.  It had
>    defined them as empty (undocumentedly) since groff 1.20 (2009).
>
> *  The doc (mdoc) macro package's `Mt` macro now sets its argument in
>    roman, not italics (or whatever the string `doc-Pa-font` was
>    configured to use).  A new string, `doc-Mt-font`, for use in
>    "mdoc.local" files and similar, supports configuration of this face.
>
> *  The doc (mdoc) macro package now performs font family switches
>    inline (that is, on the same output line) to Courier much less
>    frequently when formatting for typesetters, affecting the `Ar`, `Cm`,
>    `Er`, `Fa`, `Fd`, `Fl`, `Fn`, `Ft`, `Ic`, `Li`, and `Nm` macros.
>    This change was made to reduce the ambiguity of space widths when
>    typesetting the monospaced Courier and proportional Times fonts
>    adjacently.  Bear in mind that you can use the "mdoc.local" file to
>    customize the font used to render nearly any mdoc(7) macro's
>    arguments; this mechanism has been in place since 1992.
>
> *  The doc (mdoc) macro package's `Ql` macro now operates more simply;
>    it no longer (ever) quotes its arguments when formatting for
>    typesetters.  In practice, it does not seem difficult to distinguish
>    even single characters in Courier from those in Times.  (If it is, an
>    _explicit_ quoting macro like `Sq` or `Dq` should be used.)
>
> *  The doc (mdoc) macro package's `Lk`, `Mt`, and `Xr` macros now
>    produce hyperlinks on HTML, PDF, and terminal devices.  See above
>    regarding hyperlink support being enabled by default.
>
> *  The doc (mdoc) macro package now honors the `U` register and `MF`
>    string as the an (man) package does.
>
> *  The new macro file "koi8-r.tmac" supports the KOI8-R character
>    encoding, which supports the new Russian locale for groff.
>
> *  The m (mm) macro package now uses a 3v bottom margin rather than 2v.
>    (Using the default type size and vertical spacing, the result is a
>    half-inch margin, just like the existing top margin.)  When
>    formatting for terminals, content aligned to the bottom of the page
>    (footers, footnotes, `BS`/`BE` bottom blocks, and similar) now sets
>    one line higher than before.  Further, the margin between the body
>    text and any page footers is now 2v, like that between the body text
>    and page headers, not 1v.
>
> *  The m (mm) macro package's `Limsp` register (a GNU extension) has
>    been removed; see the item regarding the `LI` macro below.
>
> *  The m (mm) macro package's `Le` register now defaults to `1`,
>    consistently with the `Lf`, `Lt`, and `Lx` registers of similar
>    purpose, but inconsistently with DWB 3.3 mm.  Explicitly assigning
>    the `Le` register in a document's preamble works as it always has.
>
> *  The m (mm) macro package's `AST` macro (a GNU extension) is
>    deprecated, warns upon usage, and is slated for withdrawal in a
>    future release.  Assign to the new string `Abstract` instead.
>
> *  The m (mm) macro package's `ISODATE` macro (a GNU extension) is
>    deprecated, warns upon usage, and is slated for withdrawal in a
>    future release.  Assign to the new register `Isodate` instead.
>
> *  The m (mm) macro package's `EPIC` macro (a GNU extension) now
>    interprets its "width" argument in ens by default, and its "height"
>    argument in vees, instead of basic units, for consistency with the
>    rest of the package.
>
> *  Similarly, the m (mm) macro package's `PIC` macro (a GNU extension)
>    now interprets an argument to its `-I` option in ens instead of ems
>    by default.
>
> *  The m (mm) macro package no longer superscripts _and_ brackets a
>    reference mark (the `Rf` string).  Instead, the new `Rfstyle`
>    register controls its formatting.  The default, 0, selects bracketing
>    in nroff mode and superscripting in troff mode.  Set `Rfstyle` to 3
>    in a document to obtain groff mm's previous mark formatting behavior.
>
> *  The m (mm) macro package's `Li` register now defaults to 5 ens (not
>    6) to align with the `Pi` register default.
>
> *  The m (mm) macro package's `Li` register now configures the text
>    indentation of items in `RL` lists (as it long has for `AL` lists)
>    instead of hard-coding a value of 6 ens as DWB 3.3 mm does.
>
> *  The m (mm) macro package's `BVL` (a GNU extension) and `VL` macros'
>    first arguments are now optional.  If omitted, the paragraph
>    indentation amount (register `Pi`) is used for list items' text
>    indentations.
>
> *  The m (mm) macro package's `DL` macro now uses the `EM` string as the
>    mark instead of an em dash special character literal.  (The latter
>    remains the default definition of the `EM` string.)
>
> *  The m (mm) macro package's `DS` macro now interprets its third
>    argument (a right-hand indentation) in ens by default, for
>    consistency with the rest of the package.  This is a difference from
>    DWB mm (which passed the value unprocessed to the `ll` request, which
>    itself uses ems), and groff mm's own historical behavior, which used
>    basic units.
>
> *  The m (mm) macro package's `HU` macro now supports an optional second
>    argument as a GNU extension.  It corresponds to the optional third
>    argument of the `H` macro.
>
> *  The m (mm) macro package's `IND` macro (a GNU extension), now calls
>    `SK` only if no `TXIND` macro is defined, instead of performing this
>    action as part of the fallback when no `TYIND` macro is defined.
>
> *  The m (mm) macro package now supports a user-definable hook macro
>    `AFX`, which if defined is called by `AF` in lieu of the latter's
>    normal operation.  Applications include customization of letterhead.
>
> *  The m (mm) macro package now supports a user-definable hook macro
>    `RPX`, which if defined is called by `RP` in lieu of the latter's
>    normal operation (breaking the page [potentially], and formatting the
>    reference list caption string `Rp`).
>
> *  The m (mm) macro package's `LI` macro now interprets its second
>    argument as a Boolean value indicating whether a space should
>    separate the list item mark from its prefix (the first argument).
>    Thus, where you formerly specified "2" to indicate no such
>    separation, you would now use "0", matching the semantics of the
>    former `Limsp` register.  "2" continues to be recognized and handled
>    as before, but prompts a warning; migrate your documents.
>
> *  The m (mm) macro package now supports an `Aumt` string to suppress
>    the appearance of positional arguments to the `AU` macro in the
>    document heading used by memorandum types 0-3 and 6.  By default, all
>    such arguments appear, except the second (author initials).  For
>    example, a value of "3 4" more accurately reproduces London &
>    Reiser's 1978 paper describing the porting of Unix to the VAX-11/780.
>
> *  The m (mm) macro package now supports an `Rpfmt` string specifying
>    the `LB` macro arguments that the package uses to format the items in
>    an `RP` reference list.
>
> *  The m (mm) macro package now supports the `E` register as DWB mm did.
>
> *  The m (mm) macro package now supports DWB mm's `Rg` string.
>
> *  The m (mm) macro package's `nP` macro now behaves more like DWB mm's.
>    It applies a temporary indentation to the second output line of a
>    paragraph to align it with the start of the paragraph text (not the
>    tag/label) in the first, and resets the paragraph counter when the
>    first- or second-level section heading number increments.
>
> *  The m (mm) macro package's `Iso` register is now named `Isodate` to
>    make its meaning less ambiguous.  The old name remains as an alias.
>
> *  The m (mm) macro package's `Rpe` register is now named `Rpej` for
>    better symmetry with `Ej`.  The old name remains as an alias.
>
> *  The m (mm) macro package has renamed several strings to make their
>    purposes less obscure; they determine the content of captions, not
>    list items.
>      `Licon` -> `Captc`
>      `Liec`  -> `Capec`
>      `Liex`  -> `Capex`
>      `Lifg`  -> `Capfg`
>      `Litb`  -> `Captb`
>    The old names remain as aliases.
>
> *  The m (mm) macro package has renamed the `Tcst` string to `Tcstatus`
>    to make its purpose less obscure.  The old name remains as an alias.
>
> *  The m (mm) macro package recognizes new register names `Ftnum` and
>    `Rfnum` for the automatically incrementing footnote and reference
>    counters.  The old, DWB-compatible but cryptic, names `:p` and `:R`
>    remain supported.
>
> *  The s (ms) macro package now sets the vertical spacing register
>    defaults for normal (`VS`) and footnote (`FVS`) text to 120% of the
>    type size configured in the `PS` and `FPS` registers, respectively,
>    rather than 2 points larger, to comport with generally accepted
>    typesetting principles.  Thus, when formatting a document with a type
>    size of 20 points, the vertical spacing now defaults to 24 points
>    rather than 22.
>
> *  The s (ms) macro package now subtracts one vee from the footer trap
>    location computed using the `FM` register.  When using the default
>    `FM` value of `1i`, this makes the size of the margin from the footer
>    baseline to the bottom of the page 3 vees or one half-inch,
>    consistently with that between the header baseline and the page top.
>    While a bug fix, and consistent with DWB 3.3 ms, this computation is
>    inconsistent with Seventh Edition Unix ms and Heirloom Doctools ms.
>    When formatting for terminals, footers now set one line higher than
>    before.  The size of the footnote area is not affected; instead there
>    is a 1v smaller margin between its bottom and the footer baseline.
>
> Output drivers
> --------------
>
> *  grohtml(1), the (X)HTML output driver, supports a new `-k` command-
>    line option that takes a mandatory argument, either "ascii" or
>    "utf-8", which it recognizes case-insensitively.  This feature
>    configures representation of character entities in the output.  Based
>    on work by TANAKA Takuji.
>
> *  gropdf(1), the PDF output driver, now allows embedding of JFIF/JPEG
>    and JPEG 2000 image file formats.  If PerlMagick is installed, many
>    more image file formats, including PNG, PAM, and GIF, can be
>    embedded.  See also the item regarding `PDFPIC` above.  Thanks to
>    Deri James.
>
> *  gropdf now supplies its own "SS" (slanted symbol) font to improve
>    rendering of documents requiring slanted lowercase Greek letters,
>    such as those employing the eqn(1) preprocessor.  groff supplies the
>    font in PFB format, and gropdf automatically embeds it, as it is not
>    a standard PDF font.  Formerly, groff's "pdf.tmac" file defined
>    fallback characters for lowercase Greek letters, applying a slant of
>    16 degrees to the upright glyphs available in the standard symbol
>    font "S".  That technique produced glyphs slightly larger than those
>    in grops's "SS" font.  Thanks to Deri James.
>
> *  gropdf now subsets embedded fonts by default, meaning that it stores
>    only the glyphs a document actually uses.  Font subsetting usually
>    reduces the size of the PDF gropdf creates.  Thanks to Deri James.
>
> *  gropdf supports a new `--opt` command-line option, permitting a few
>    features, including font subsetting, to be selectively enabled.
>    Thanks to Deri James.
>
> *  gropdf now emits PDFs that conform to the PDF 1.7 standard (also
>    known as ISO 32000).  Its new `--pdfver` command-line option permits
>    production of PDF 1.4-conformant output instead.  Thanks to Deri
>    James.
>
> *  gropdf supports a new `pdf: pagenumbering` device extension command
>    and `pdfpagenumbering` convenience macro, allowing control of the
>    page numbers in a PDF reader's overview panel.  It is common for a
>    document to number early pages with Roman numerals and then restart
>    page enumeration at decimal 1 for its main matter.  Thanks to Deri
>    James.
>
> *  gropdf now offers its own implementations of the "pdfmark" macro
>    package's "pdfhref" and other macros, supporting internal (bookmarks,
>    named destinations) and external (URL) hyperlinks, and the
>    specification of hotspots for link text.  For example, when bundling
>    multiple man pages into a collection, as the supplied
>    groff-man-pages.pdf document and the Linux man-pages project do,
>    references to man pages within the collection are supported with
>    internal hyperlinks, and those outside with external ones.  Thanks to
>    Deri James.
>
> *  gropdf now supports characters outside the Unicode Basic Latin subset
>    in bookmarks, named destinations, and external hyperlinks.  (They
>    must be encoded using groff's Unicode special character escape
>    sequences; the preconv preprocessor is helpful to simply this
>    requirement.)  Thanks to Deri James.
>
> *  gropdf now recognizes a `GROPDF_OPTIONS` environment variable,
>    interpreting it as a space-separated list of command-line options.
>    Explicit command-line options override any settings from this
>    environment variable.  You can use this variable to obviate passing
>    options to gropdf via groff's `-P` option.  Thanks to Deri James.
>
> *  grops(1), the PostScript output driver, now supports fonts encoded
>    using UTF-16.  Indicate the encoding by including the string
>    "-UTF16-" within the font's name as specified by the "internalname"
>    directive in its font description file.  Thanks to TANAKA Takuji.
>
> *  The PostScript output driver grops(1) no longer accepts spaces as
>    field separators in its "download" file; this is so that spaces can
>    appear in font file names, and to better align the syntax of this
>    file with that used by gropdf(1).  The download file for grops
>    shipped by groff has long used tabs rather than spaces for field
>    separation.
>
> *  The PostScript output driver grops(1)'s macro file "ps.tmac" no
>    longer defines fallback special characters `\[S ,]` and `\[S ,]` to
>    simulate support for what Unicode calls LATIN {CAPITAL,SMALL} LETTER
>    S WITH COMMA BELOW.  The file's definition constructed these glyphs
>    by overstriking the Basic Latin "S" (or "s") with a cedilla accent,
>    which is regarded as less orthographically acceptable than in the
>    past.  A user's document or macro file can still do exactly what
>    "ps.tmac" used to.
>
>      .fchar \[S ,] \o'S\[ac]'
>      .hcode \[S ,]s
>      .fchar \[s ,] \o's\[ac]'
>      .hcode \[s ,]s
>
> *  The PostScript output driver grops(1) once again accepts a file name
>    containing slashes as a document prolog or resource (such as a font
>    to be downloaded into the document).  This is a restoration of groff
>    1.22.4 and earlier behavior; groff's 1.23.0 change of not accepting a
>    file name containing slashes as an encoding or font description
>    remains in place.  (We impose this restriction because the output
>    driver interprets the contents of these files; it does not interpret
>    the PostScript prolog or resource files.)
>
> *  grotty(1) now supports devices recognizing ECMA-48/ISO 6429 SGR 38
>    and 48 escape sequences that select RGB colors using 8 bits per color
>    channel.  A new command-line option, `-t`, configures emission of
>    these escape sequences instead of the SGR 30-37 and 40-47 sequences
>    supporting 3- or 4-bit color.  Thanks to Deri James.
>
>    Example:
>
>    $ groff -T utf8 -P -t <<EOF
>    .defcolor pink rgb #ffc0cb
>    .defcolor springgreen rgb #00ff7f
>    Hello, \f[B]\m[pink]colorful \m[springgreen]world\m[default]\f[]!
>    .pl \n[nl]u
>    EOF
>
> *  gxditview(1), the X11 output driver and document previewer, now
>    accepts the option `-v` as a synonym of `--version` (and `-version`).
>    This change aligns it with other groff output drivers, and makes it
>    work correctly with "groff -vX".
>
> Utilities
> ---------
>
> *  afmtodit now recognizes a '-q' option to suppress diagnostics
>    reporting duplicate mappings in favor of a count thereof, and the
>    "BuildFoundries" script uses it.  Recent versions of the URW fonts
>    have tons of duplicate mappings (for groff's purposes) and to our
>    knowledge these are all harmless.
>
> *  grog no longer supports the `--ligatures` and `--run` options.
>    Simulate the former (which was specific to the "pdf" output device)
>    with the option sequence "-P -U -P y", and the latter by using the
>    command substitution feature of your shell; see section "Examples" of
>    groff(1).
>
> *  groff now offers install-font.bash, a shell script that interactively
>    assists the configuration of fonts for use with the GNU troff
>    formatter and the gropdf and grops output drivers.  For now, it is
>    provided as an example, as it lacks a man page.  You can change to
>    its directory and run "bash install-font.bash -H" for a man page-like
>    description of its features and operation.
>
> Miscellaneous
> -------------
>
> *  The contributed programs gperl and gpinyin no longer accept
>    abbreviated forms of the long options `--help` and `--version`.  The
>    respective synonymous short options `-h` and `-v` remain.
>
> *  Font description files now support a variant of the "charset"
>    directive: "charset-range" works like the existing "charset"
>    directive except that the glyph descriptions use a `name` of the form
>    "uEEEE..uFFFF" (where "EEEE" and "FFFF" are hexadecimal digit
>    sequences), and apply the metrics identically to all glyphs in the
>    designated range.  Thanks to TANAKA Takuji.
>
> *  groff now ships font description files usable with the "ps", "html",
>    "xhtml", and "utf8" output devices to support East Asian fonts.
>    (Caveat: with few exceptions, groff does not ship font files
>    themselves.)  These are intended as abstractions of faces to permit
>    consistent naming while allowing custom font selections, just as with
>    the 12 text typefaces supported across output devices for Latin
>    scripts in groff (three families of four styles each).  These CJK
>    font descriptions are not organized into groff font families, but are
>    similarly arranged.
>
>       CSH: Simplified Chinese, Hei style
>       CSS: Simplified Chinese, Song style
>       CTH: Traditional Chinese, Hei style
>       CTS: Traditional Chinese, Song style
>       JPG: Japanese, Gothic style
>       JPM: Japanese, Mincho style
>       KOG: Korean, Gothic style
>       KOM: Korean, Mincho style
>
>    Thanks to TANAKA Takuji.
>
> *  The commands addftinfo, grodvi, post-grohtml, grolbp, grolj4, grops,
>    grotty, eqn, pre-grohtml, gxditview, pic, preconv, refer, soelim,
>    tbl, groff, troff, hpftodit, indxbib, lkbib, lookbib, tfmtodit, and
>    xtotroff now exit with status 2 instead of 1 on usage errors.  grn
>    now exits with status 2 on a usage error instead of a successful
>    status (0).
>
> *  Support for terminal devices using the CCSID 1047 (EBCDIC) encoding
>    has been withdrawn.  This change partially clears the way for GNU
>    troff to interpret UTF-8 input directly (without preconv(1)
>    preprocessor usage) in the future.  Use iconv(1) to covert a code
>    page 1047 document to US-ASCII or ISO Latin-1 prior to its input to
>    GNU troff.  preconv(1), and therefore groff(1)'s `-k` and `-K`
>    options, can do this as well if preconv is built with iconv support.
>    Use `preconv -v` to determine this fact.
>
> *  groff's "configure" script now tries harder to determine an
>    appropriate paper format for the system; its output reports how it
>    made its determination.  Any existing "/etc/papersize" file is one of
>    the resources it consults.
>
> *  groff's "configure" script now supports a "--without-urw-fonts"
>    option, for use on systems where the URW replacement fonts for
>    PostScript and PDF standard fonts are unavailable or not desired.  It
>    also silences the lengthy warning the script issues when these fonts
>    and their metric files are not found.  Configuring without URW font
>    support reduces the gropdf(1) output driver's functionality; see
>    subsection "Feature service levels and URW font support" of that man
>    page for details.
>
> *  You can now specify any paper format you like--including the file
>    specification "/etc/papersize" for systems using "libpaper"--as the
>    default that the groff build writes to generated device description
>    files ("DESC") for the "dvi", "lbp", "lj4", "pdf", and "ps" output
>    drivers.  (The paper format must still be valid; see groff_font(5).)
>
>      Example: ./configure PAGE=/etc/papersize --prefix=/opt/gnu
>
> *  Building groff no longer requires the PSUtils package.
>
> *  Building groff no longer requires the makeinfo command.  Since groff
>    1.23.0, we ship groff's Texinfo manual in several formats as part of
>    groff's distribution archive.  We ask that distributors provide their
>    users with all formats appropriate to the platform (GNU Info, HTML,
>    plain text, TeX DVI, and PDF).  Thanks to onf.
>
> *  Polish language input documents are now supported, including
>    hyphenation patterns from the CTAN project and localized strings
>    for the man, ms, me, mm, and mom packages.  Thanks to Dariusz
>    Chilimoniuk.
>
> *  Russian language input documents using the KOI8-R encoding are now
>    supported, including hyphenation patterns from the ruhyphen project
>    and localized strings for the man, ms, me, mm, and mom packages.
>    Thanks to Nikita Ivanov.
>
> *  Spanish language input documents are now supported, including
>    hyphenation patterns from the hyph-utf8 project and localized strings
>    for the man, ms, me, mm, and mom packages.  Thanks to Eloi Montañés.
>
> *  The localization macro files now set up an appropriate hyphenation
>    mode default.  For Chinese and Japanese, this is zero.
>
> *  If groff programs have their current time overridden by the
>    SOURCE_DATE_EPOCH environment variable, then that time is always
>    displayed in UTC.  That environment variable is normally only set
>    when specifically requesting build systems to produce reproducible
>    output, and it is useful for reproducibility test harnesses to vary
>    the TZ environment variable and ensure that it does not affect the
>    output of the build; those harnesses have no way to set TZ=UTC only
>    for groff programs.  People setting SOURCE_DATE_EPOCH are likely to
>    be more in the "system programmer" camp as described in the release
>    notes for 1.23.0, so it is easier to defend time-zone-invariant
>    output to them.  In all other cases, the current time remains
>    displayed in local time.  Thanks to Colin Watson.
>
> *  The minimum version of Perl required to build groff is now 5.8 (18
>    July 2002), incremented from 5.6.1.
>
> *  groff now looks for the Netpbm program pamcut(1) rather than
>    pnmcut(1).  Per its developers, the former was introduced in 2001
>    ago and the latter withdrawn in 2009.
>
> *  The Makefile macro `DEVICE` has been renamed to `DEFAULT_DEVICE`; be
>    aware if your builds don't use "ps" as the default output device.
>
> *  The groff_diff(7) man page no longer contains examples.  They remain
>    in groff's Texinfo manual.
>
> *  groff's Texinfo manual now adapts its content to the groff command
>    prefix configured at build time.  If the build is configured without
>    a leading "g"--omitting it has been groff's default for many years,
>    possibly forever--then our Texinfo manual now omits that prefix when
>    mentioning the affected commands (all replacements for AT&T troff
>    commands).  This way, if you select a command prefix, say "limbo",
>    and rebuild the Texinfo manual, the manual reflects the prefix used
>    by your build configuration, and talks about "limboeqn",
>    "limbotroff", "limborefer", and so on.
>
>
> Acknowledgements
> ================
>
> We'd like to thank the following people for helping ensure the quality
> of this release.
>
> Alan Coopersmith
> Alex Colomar
> Alexander Kanavin
> Alexander Monakov
> Alexis (flexibeast)
> Alexis Hildebrandt
> Andreas Kusalananda Kähäri
> Andrew Bower
> Axel Kielhorn
> Benno Schulenberg
> Bjarni Ingi Gislason
> Brian Inglis
> Bruno Haible
> Carsten Kunze
> Christof Meerwald
> Colin Watson
> Collin Funk
> Damian McGuckin
> Dan Plassche
> Dariusz Chilimoniuk
> Dave Kemper
> Deri James
> Doug McIlroy
> Duncan Losin
> Eli Schwartz
> Eloi Montañés
> Frazer Williams
> Frederic Chartier
> Gavin Smith
> Gene
> Grisha Levit
> Günther Noack
> Hanno Boeck
> Hans Bezemer
> Heinz-Jürgen Oertel
> Helge Kreutzmann
> Helmut Grohne
> Ian Ropers
> Ingo Schwarze
> James Cloos
> James Youngman
> Jeff Conrad
> Joerg van den Hoff
> John de Armas
> Jonathan Gray
> Ken Mandelberg
> Larry Kollar
> Lennart Jablonka
> Lukas Javorsky
> Martin D. Kealey
> Michał Kruszewski
> Mike Fulton
> Morten Bo Johansen
> Nelson H. F. Beebe
> Nikita Ivanov
> Norwid Behrnd
> Oliver Corff
> onf
> Patrice Dumas
> Paul Eggert
> Peter Chubb
> Peter Schaffter
> Phil Chadwick
> Pim
> Ralph Corderoy
> Rob Kolstad
> Robert Yang
> Ross Burton
> Russ Allbery
> Sebastien Peterson-Boudreau
> Stefan Möding
> Sven Schober
> T. Kurt Bond
> TANAKA Takuji
> Tadziu Hoffman
> Thomas Dickey
> Thorsten Glaser
> Thérèse Godefroy
> Walter Alejandro Iglesias
> Werner Lemberg
> наб
>