henry (03/17/83)
In format, changing the page length (.PL) inside a keep (.KE-.EK) can really mess things up. It can make nroff croak with a very uninformative message, or do other unkind things like silently producing no output whatsoever. This combination cropped up in an attempt to squeeze a bit more text onto a page (so that a small change could be incorporated without messing up later pagination).