No worries, all is well.  The abbreviation is very widely used, including on the city's website, so the unabbreviated form can definitely seem odd.  In the end, though, it's just an abbreviation, so the policy on abbreviations kicks in.  

I know you've done a lot of great work on Chicago, and STL would benefit from similar work if you are so inclined.  It doesn't have very many regular mappers.  I jump in and work on the city from time to time, but there's still a lot to be done.