Best practices for Da Capo/Dal Segno/al Fine/etc.

[Joel C. Salomon]

… what is the current (2.19) best practice for typesetting the Da
Capo/‌Dal Segno/‌al Fine/‌etc. repeat marks?

(Last time I saw this come up on the list, the discussion became about a
proposed input syntax, `\repeat coda {…} \alternative {…}`––which I’ll
certainly use if & when it’s implemented, but for now it seems I need to
hard-code it.)

At <https://music.stackexchange.com/questions/46232/da-capo-in-lilypond>
I’ve found this code:

    \once \override Score.RehearsalMark #'break-visibility = #'#(#t #t #f)
    \mark \markup { \small "D.C. al fine" }

but that leaves the mark above the score and centered over the final
bar-line––i.e., hanging into the margins.

Two years ago on 2016-02-01, in thread “D.C. al fine”
(<http://lilypond.1069038.n5.nabble.com/D-C-al-fine-tp186747.html>/‌<https://lists.gnu.org/archive/html/lilypond-user/2016-02/msg00014.html>),
Graham King suggested a version that also adjusted the marks’ alignment.
 But then Brian Barker pointed out that this was typographically
incomplete, and quoted Elaine Gould with some more details––but if
anyone in the discussion implemented this in code it was not posted to
the list.

Searching LSR (<http://lsr.di.unimi.it/LSR/Search?q=al+fine>) again
turned up parts of solutions: multiple marks, complex ways of placing
such marks, etc.––so I know *approximately* what needs to happen, but
I’m still left without a concrete example.  Has anyone put one together
that I’m just not finding?

(Though I suspect my I’ll end up needing something like
<http://lsr.di.unimi.it/LSR/Item?id=976> since the score I’m setting has
both “Fine” and a fermata mark attached to the same bar-line.)

––Joel C. Salomon