shower drain & p trap code question

Watching some TLC tonight on some home improvement show and this guy says that according to code, compression fittings on a shower p trap can't be used in an area where you can't get to - the example on the show was a second floor bathroom between floor joists. Is this true? Does everything have to be glue joints?

I'm in a 30 yr old house, 2nd floor bathroom - only access from 1st floor would be through the kitchen ceiling.

Compression fittings on tub drains have been around since long before glues pipe. I have heard that some local codes don't allow them, but in general I think you can still use them.

joints

Usually the prohibition is about what kind of compression joints you use.

It looks like this one - I'm assuming the twisty part is the compression fitting. Am I wrong?

http://www.idealtruevalue.com/servlet/the-14885/Detail

trap

The compression part is the inlet. The large nut is a ground joint. But regardless, I would NEVER use that trap in a concealed location. I have seen too many of them with snapped locknuts at the ground joint.

That's enough evidence for me - I'll take it back. Thanks for your help.