At https://www.gnu.org/software/groff/manual/groff.html (5.37 GNU troff
Internals), there is an example using the ".pline" request; this is
supposed to display internal nodes:
printf 'Gi\\[:u]\\%%seppe\n.pline\n' | groff -z 2>&1 | jq
With groff 1.22.4 this fails because groff says .pline is an unknown
command.
I thought maybe a.pline request which outputs was added in a more recent
release, however "pline" is not described anywhere in the above html manual.
(Also: Was -z or -Z intended? "jq" is a JSON processor on my system.)
