[Groff] { and } troff output commands

[Werner LEMBERG]

Dear friends,


from time to time I find new, undocumented stuff in groff.  The latest
two things are the troff output commands `{' and `}' which push
resp. pop the output environment.  It can be found in
src/libs/libdriver/input.cc, line 230ff.

Apparently, it isn't used by GNU troff.  According to the log file,
this has always been in the code (at least since the ChangeLog file
exists).

Is there a program which uses this feature?


    Werner