But you only find something about attributes in perlfunc because my was specially added to perlfunc; my isn't a function. The details are in perlsub, where you would also go for punctuation as prototypes and some cases of parenthesis.
Why do you say that my isn't a function? (I'm not arguing, just curious.) Do you mean it in the Lispy sense that it's a ‘special form’ (meaning, I suppose, that I couldn't write it myself in plain Perl)?
I was just suggesting that :-for-attribute-list could be mentioned in perlop because it affects parsing (which is, after all, what one is trying to figure out when looking at a precedence table), not because it is itself an operator; but, aside from the fact that that idea probably doesn't make much sense on its own (should we mention every interaction of symbols?), what ikegami had said eventually sunk in and I realised that there's no reason to document the effect of trying to write officially undefined code.
Not that I know of. But by all means, feel free to write up a list and submit is as a patch. Writing documentation doesn't require any coding language, which means most people can do it.
The problem is that, as I say, I don't know the contents of such a list, and I'm not sure how I could figure it out. “Officially undefined” is basically an act of will on the part of the language designers; there's no way for me alone to tell the difference between “behaves this way but undocumented” and “behaves this way by chance, but is explicitly allowed to be changed on a whim”—because the difference is not in the code, but in the will of (I guess) the pumpking.