[Sagitta]

A lot of cities are listed dually.

There are also other quirks. The tiny town (village really) I live in is not listed, yet the neighboring community that uses our post office is, and its listed under that town's name with the combined population of both it and here.

The best bet is just to go into the cities.txt and do a search for any sizable town that is missing and see if its listed with another. Failing that, try looking for a neighboring community and see if its listed under that instead.