I've also noticed that in the US, the abbreviations leave out the "of" whereas we leave them in (for the most part): U of M (Manitoba) not UM, U of T (Toronto) not UT, U of A (Alberta) not UA, etc. Rarely just letters (although there are a few - UBC, and my school, MUN). Sometimes the name is chopped off and "university" left out so you have Dal for Dalhousie, Mac for MacMaster, etc.