I guess maybe an easier way to look at it is: Think like a computer.

0's and 1's, black or white.

There is no real way to fully explain to PBS exactly what you want.

I remember flying with a senior FO on the -er, he commuted out of seattle to ATL and could have held anything he wanted anytime he wanted it. His multiple preference qualifiers made his bid so complex that he flew nothing but bogota trips for 3 or 4 months. He commuted to a crappy 3 day worth nada, when he was able to hold rome or any german city he wanted during octoberfest.