Only in some orgs
The 308 class does not exist in all orgs, though I think now it does in a lot of them, just not the IPF. And let's not mention those funky NASA weight classes. The only one I remember is the 227s, WTF is up with that.
I don't know how common it is, but the ADFPA used to have the 319 class, and I think I have seen it since the USAPL(used to be ADFPA) became the IPF affliate. Just don't remember where, may be the APA.