In my contact list I have a place called Peter's Po-Boys with 2 different phone numbers. In the list of labels there is mobile, home, work, main, etc, etc.... If you scroll all the way down you'll find "Add Custom Label". I added "Hattiesburg" and "Petal" and placed those next to the appropriate phone number (rather than "work" which was the best previous choice I had.....or so I thought!)
Both "Hattiesburg" and "Petal" are now in the list of labels. I'm now sitting here trying to think of other labels that I might want to add!