Adding a "best of" episode of a TV show

If a TV show includes a "best of" episode which has no new footage, only clips of previous episodes, should the episode still be added?

If yes then how should the data be added? Do I use normal numbering, e.g. this episode aired as the 5th in season 1, so enter it as 1.5, or in some other way? And do I leave the cast and crew empty, or still credit them with some attribute?

If not then should I document the episode in some other way? For example, I could add it as a Trivia item, though not sure where exactly - on the series level or for the preceding and/or following episode(s)?

Thanks in advance!