The sixteen are:
XYZZY (cobble crawl)
PLUGH (Y2)
FEE (Giant room)
FIE (Giant room)
FOE (Giant room)
FOO (Giant room)
MELENKURION (tool room)
ZORTON (sword stone)
THURB (ice tunnels)
NOSIDE (Sorcerer's Lair)
SAMOHT (Sorcerer's Lair)
PHUGGG (Djinn)