Noticed an inconsistency in the "existence" of the generic city code TYO: if you don't select an airline, TYO is recognized. If you select SQ or some others, TYO becomes non-existent.

I can understand in the example case of AM: you can select NRT but not HND, so it follows that there's no benefit to selecting TYO (but still why bother eliminating it?)

But it doesn't make sense in the case of SQ, because you can in fact select either NRT or HND. So in effect you need to do two separate searches, which is annoying due to the horribly slow site and the potential CAPTCHA encounters.

Didn't check but assuming that similar can be observed with NYC, LON, PAR, etc.