man.hyphenate.filenames — Hyphenate filenames?
If zero (the default), hyphenation is suppressed for
filename output.
If hyphenation is already turned off globally (that is, if
man.hyphenate is zero, setting
man.hyphenate.filenames is not
necessary.
If man.hyphenate.filenames is non-zero,
filenames will not be treated specially and are subject to hyphenation
just like other words.
If you are thinking about setting a non-zero value for
man.hyphenate.filenames in order to make long
filenames/pathnames break across lines, you'd probably be better off
experimenting with setting the
man.break.after.slash parameter first. That
will cause long pathnames to be broken after slashes.