College Football -- replay rule?

[Headhunter13]

What is the replay rule in college football? Does it vary by conference? I always thought that there was a replay official and he/they reviewed the plays. A coach can call timeout and hope that the extra time gives them (replay officials) time to review it .... but can a coach/team ask?

Referring to the OSU/Ill game where the Illinois fumble wasn't reviewed and the Big Ten later apologized for that. Could Tressel have asked for it to be reviewed?

Thanks,

--Headhunter