Originally Posted by
yyznomad
I like the use of "X". Is that a convention or just something you did?
For me, off the top of my head:
XHKG
XIST
XMDT
Maybe one day I can say XTXL (or never, given the state of BER affairs)

Borrowed the idea from flightmemory!
Also, I should have said that XIST is still used for cargo flights.
Still thinking about other airports...for terminals no longer extant, FNJ (Pyongyang) comes to mind.