It's supposed to be an airport which has certain services or has been desognated as an entry airport (see AIM P/CG) but, as it says in AC-150/5000-5c
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UNOFFICIALLY NAMED INTERNATIONAL AIRPORTS.
In addition to the designated international airports discussed above, there are a number of airports in the United States that contain the word ''International" within their names but have no official designation Nothing prohibits this practice, though it is discouraged. However, without any official designation, these airports have no international status.
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