In some cases, reversal of series orders that never aired.

https://tvline.com/lists/tv-shows-cancelled-quickly-short-lived-series-photos/the-beautiful-life-tbl-the-cw/

Cool topic!

The link mostly focuses on newer series, but includes some older ones, too. No mention, though, of Co-Ed Fever, which might have the record for "worst opening theme of all time". Only one episode aired in the US, though eight were produced. Today it's mostly remembered for its sets, which were reused on The Facts of Life's first season.

I remember Highcliffe Manor (https://www.youtube.com/watch?v=ApmzA9Bxyu8), a horror sitcom which only aired for four episodes (two more were unaired).