User blog comment:Rappy 4187/Technical Update: March 10, 2015/@comment-1251315-20150312231408/@comment-1251315-20150312232006

I should note that this flag is not consistent. For example, I am a sysop on two wiki's, but only the Homeworld Wiki gives the "poweruser" flag, not the other. I'm also getting the "poweruser" flag in wiki's where I'm not even actually a sysop at all, but just have a number of user rights. Even users who only edit on a single wiki and have rollback (for example) are getting the poweruser flag as well.

So whatever this is meant to be, looks to be unexplained and random.