Commas

Q. Are phrases regarding the location of something deemed restrictive or not? Must one know whether only one exists in order to insert commas? I know it is always “the White House, in Washington, D.C.” But must it also then be “Bob’s Hardware in Dallas” when I do not know if there are other places that go by the same name? If I encountered “Bob’s upstairs neighbor Bill,” and didn’t know if he lived below one person or on the second floor of a ten-story building, I would have to make it restrictive, yes? So wouldn’t the same rule apply here? I work for a weekly magazine without a research department and this question has been preying on my frazzled mind for some time—please help!

A. I must admit that this problem has never crossed my mind—probably because copy editors rarely have the time and resources to check every fact they read and must therefore allow a certain amount of ambiguity in order to get through the day. When the facts are unknown, I would treat the phrase as though it were restrictive, with the reasoning that it’s cleaner and easier to omit the commas.