Commit b9c70aa59 deprecated .hpfcode.

This is not quite in scope for this ticket, which proposes to list things that may be deprecated in a future release, whereas this is a thing that is deprecated now (as of the next release, which is the earliest that might include this list).  But users might benefit from the list including it anyway, to give it higher visibility than the warning emitted if they should stumble across it.

The extensive commit log entry for commit c3284103 suggests that deprecating www.tmac is on the lead developer's radar.

That might warrant its own ticket.  On the other hand, if this ticket gets its way, there'll be a user-facing list of deprecation candidates, which developers can also use as a reference and not necessarily need separate tickets for each item, especially in cases where the deprecation entails nothing more than notifying users for the foreseeable future.  (In particular, www.tmac is old and large enough that it (presumably) wouldn't be removed until equivalent support is added to most full-service packages, suggesting a long timeline.)

comment #4:

> comment #3:
> > besides hdtbl there are deprecation proposals in at least bug
> > #63142, bug #64337, bug #64353, and... bug #59425.
>
> and now bug #64515.

and now bug #64579 (though the proposal itself was previously buried in a two-years-older bug report).

comment #2:

> Narrowing scope to the thing specifically contemplated.

The intended purpose of this ticket was the "make an official list [of things to deprecate]" task, as referenced in the original submission.

I agree that deprecating hdtbl warrants its own ticket, but distributing a list of things under consideration for deprecation also seems to warrant an action item of some sort.  Just in this bug tracker, besides hdtbl there are deprecation proposals in at least bug #63142, bug #64337, bug #64353, and the aforementioned bug #59425.

While I was in favor of killing off groffer, and it was done with list unanimity (http://lists.gnu.org/r/groff/2020-04/msg00051.html), there was little forewarning to users who don't keep up with groff development--there was no groff release that included it but warned that it was deprecated--and there have been a couple postmortem lamentations (e.g., http://lists.gnu.org/r/groff/2021-04/msg00032.html, http://lists.gnu.org/r/groff/2023-07/msg00063.html).

So it would be helpful to users who don't follow groff development to have more of a heads-up that things might disappear in the future.  Probably anyone who cares about changes to grout follows our email list, but I feel deprecating things end users might use warrants some prepublicity.

For deprecation consideration: In bug #54461, one developer characterizes hdtbl as "totally unmaintained" and another says "If the component is totally unmaintained then we should drop it from the groff distribution."