Is there a rule for how tv series are specified by season in the title? Most of my tv series use colon separators, e.g., "Mad Men: Season One", but I was just entering the complete "Hamish Macbeth" series and the existing profile for series 1 used a comma, e.g., "Hamish Macbeth, Series One" while the other two series have no separator at all, e.g., "Hamish Macbeth Series Two".

I looked in the contribution guidelines and I didn't see a specific rule for this.

The colon comes from the general title rule:

Episode descriptors are part of the title; separate them with a colon and space; e.g. "Star Trek III: The Search for Spock". For multiple descriptors, use a colon and space for each break.