User:SOTO/Forum Archive/The Panopticon/@comment-26975268-20130201045831/@comment-88790-20130306133200

It could be that they're using the actual on-screen title cards for the numerical spellings.

To take a random set of stories;

The War Machines uses numbers; "Episode 1"

Inferno spells it out in full "Episode One".

As does Logopolis "Part One".