Probably not in the infobox.  If it's reliably sourceable as common and consistent, then include it in the infobox field. Note that this means RS say it's commonly used. Cherry picking  it does not qualify, per WP:NEOLOGISM. If it does suit that sourcing requirement, I'd still probably argue against it, because it's a local colloquialism, thus trivia; if people outside this area do not refer to it this way, then the nickname is not of encyclopedic importance. Contrast "the Big Apple" for New York City, a nickname with which virtually all Americans and probably most native English speakers are familiar.  belongs in a city article's infobox (and maybe its lead). It's reasonably likely that some RS can be found saying that "the 'Burg" is a common nickname of St. Petersburg FL, but I'd bet good money they're mostly or entirely local, or that they say it's used by locals. PS: If it were used in the infobox here, it should be as sources most often give it, which nom suggests is "the 'Burg", not "the Burg". It wouldn't be capitalized with "The" in either case, per MOS:CAPS, even if a few sources capitalize it that way.  —  ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼