I'll admit I wasn't a football fan when the Baltimore Colts left, I was born five years after that. HOWEVER, I have been around enough folks in Baltimore to develop a venomous hatred for team in Indianapolis rivaled only by my dislike of the Steelers. What has irked me is as a Ravens fan, I've always been told to refer to Peyton Manning's team as "The football team from Indianapolis" or the "Indianapolis Professional Football Team." and most Ravens fans I talk to don't. When visiting teams are introduced they're called "The New England Patriots" or w/e but the PA announcer always called Indianapolis, "The Indianapolis Professional Football Team."
Maybe it's because I'm fresh out of college, and I'm still very much so into rivalries but I feel like most fans don't have a sordid grasp on what it means to be a fan of Baltimore football.
I like to think referring to them as the Football team from Indianapolis, is as proper as using correct punctuation and spelling.