PHIG was supposed to be a joke. Some insisted that it should not be called a C12k (which was based on it being advertised as a 12k hone), and stated that it is not a 12k hone. So that lead some to ask why it's not a 12k stone, and the reason is that it is a natural stone, and natural stones cannot have fixed grit ratings. So, based on all that, I started calling it the Peoples' Hone of Indeterminate Grit, and somehow that stuck.

I'm sure no one will care what you call it, just so long as we know what hone you are referring to.