Ok thanks for the reply. I thought I'd ask before going down the custom format route.

I'm using {plex.name} which is awesome as it sorts out difficult names like 24 has with colon's etc.

24 - S02E01 - Day 2 - 8.00 A.M. - 9.00 A.M.mkv

Is there a simple way to force the season and episode characters to lower case using {plex.name}?

24 - s02e01 - Day 2 - 8.00 A.M. - 9.00 A.M.mkv