A (three-letter location identifier) can be for a government-agency.Logical formLearned from530 sentences. Airports may use a (three-letter location identifier).Logical formLearned from425 sentences. An identifier can be personal.Logical formLearned from287 sentences. Identifiers can be persistent.Logical formLearned from286 sentences. An identifier can be persistent.Logical formLearned from173 sentences. Identifiers may undergo a use.Logical formLearned from161 sentences. (Pill imprint identifier) may undergo a use.Logical formLearned from124 sentences. Some airports may use a (three-letter location identifier).Logical formLearned from107 sentences. An identifier may undergo a use.Logical formLearned from99 sentences. Identifiers may be linked to subjects.Logical formLearned from87 sentences. An identifier can be universal.Logical formLearned from86 sentences. An identifier can be numerical.Logical formLearned from78 sentences. An identifier may pertain-to an airport.Logical formLearned from75 sentences. An identifier can be global.Logical formLearned from74 sentences. A list can be constituted-of-or-filled-with identifiers.Logical formLearned from71 sentences.