I guess my point is - is it a standard? And if it isn't should it be? If it is a standard.

It provides benefit to both IDEs and humans, although the benefit to humans is rather limited in well purposed classes.

If it were a standard, then it should be implemented everywhere, or in well-defined situations. I am coming at this from a different perspective probably, as I don't use PHPStorm and at the moment I can guess quite acurately which editor a developer is using by looking at the code, which I shouldn't be able to do imo.