The title for Transactors Improv Company's new show at Manbites Dog Theatre is a 22-letter acronym: TEEFMSSSPTIC:IYSTOYNSTB*. But forget the alphabet soup: Here's what you really need to know. In recent years, Transactors have gradually morphed from an award-winning comedy troupe into a group unafraid to explore improvisational drama as well as humor. Call it "instant theater," where the group assembles sketches and scenes from key details the audience provides, on demand. Pay what you like Wednesday night; $10 Thursday; $15 Friday and Saturday. 682-3343. (*TEEFMSSSPTIC:IYSTOYNSTB, is for: "The Exciting, Entertaining, Funny, Musical, Sometimes Shocking, Sometimes Poignant Transactors Improv Co.: If You've Seen Them Once You've Never Seen Them Before). Yep, that just about sums it up.