It might be helpful to develop a "This article is NOT" list to allow the existence of a useful nicknames list and prevent scope creep:
 NOT a list of mottos, slogans, and marketing tags; nearly every city has one or more such "nickname".  Examples: The Big Apple, Garlic Capital
 NOT a list of humorous names; nicknames listed here, if once humorous, are common enough to have lost their humorous effect
 NOT a comprehensive list of variants; the one or two nicknames listed here for a given city are recognized city-wide as ****the standard**** spoken shortcuts for the full city name.
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