Finally found the wording that some PTAs use to argue that they shouldn't be fundraising for things like playgrounds.... It is not in the bylaws, although supporters argue that it is based in bylaws, specifically in what is usually the "purposes" section. No where is it listed in the purposes of the PTA to raise money to buy things for schools/students; it's all loftier stuff like "secure adequate laws for the care and protection of children and youth" and "develop between educators and the general public such united efforts as will secure for all children and youth the highest advantages in physical, mental, social, and spiritual education." And those people think that since the bylaws don't say you *can* fundraise for certain things, then you can't.
In the National PTA's "Money Matters" publication, a policy manual which addresses treasurers' reponsibilities and fundraising policies, there is this sentence:
A PTA renders a greater service by working to secure adequate funding for programs that have a more enduring benefit than purchasing equipment for schools.
I've seen this sentence paraphrased in a few different ways on several state websites, usually in a fundraising section.
BUT, to rely on this one sentence (which seems to be pretty common, as Tim notes) is to really take the thing out of context. PTA people should take a look at that whole "Standards for PTA Fund-Raising" section (page 16 of "Money Matters"--it's available on the PTA website), but I think it's pretty clear in there that individual PTAs still have quite a bit of leeway. It does say that "each PTA must decide what it will do."