A few days ago, a patch from <G dot Branden dot Robinson at gmail dot com>

A few days ago, a patch from <G dot Branden dot Robinson at gmail dot com>
got committed to groff which changed .TP from using .it to using .itc,
such that groff now supports more than one man(7) macro line in the .TP
head if all but the last line in the head end with \c.

Of course, relying on that behaviour is utterly non-portable, but if
authors are reckless enough to use that idiom, let's do what they want.