Well, I guess it really goes by what the local codes are rather than the IRC or the UPC. There are a few locals that I know of, one being the city of Elmhurst Il, that require a drum trap be installed on a tub. Take a look at step 27.27 d) on page 10 of this link:
http://www.elmhurst.org/elmhurst/cle...lmhurstT27.pdf
I agree, it's a buyer beware market out there, but the the local authority may not have a problem with it. Just depends I guess. Anyhow, thanks for the info, appreciate the references.
What type of trap is one to use under a sink that drains through the floor if not an S trap. Or is the rule for no new installations of an S trap.