When sage.org used to be a thing, this was a list that attempted to describe what a System Administrator at various levels did. It can morph with some effort into describing some DevOps (OK more infrastructure oriented people). I seem to remember there was an effort for levels beyond SAGE IV, but cannot find any reference to it, nor any links from the Internet Archive. It is a pity that USENIX let both the domain and its content lapse from the web.