If you run into a port with a USE_GROFF, think twice before removing it! If you remove it, then you depend on mandoc doing the right thing in replacing groff. Which means showing a correct result for now, *and for later*.
There are constructs mandoc does not handle. There are constructs mandoc somewhat ignores, silently by default. Before removing USE_GROFF, you definitely should try out mandoc -Wall *and read the errors and warnings*. When in doubt, check with Ingo. But if the result is not squeaky clean, there is a chance a future update of mandoc *will break the page*. Hence the USE_GROFF...
