Board Thread:General Discussion/@comment-22224-20180521161500/@comment-24155515-20180524150547

Pseudo-Vector the CSS code? It's intended for use in Monobook. Unless someone gets super exciting with their Oasis enhancements, it'll become useless without that skin or make changes to Oasis that weren't really intended.

PseudoMonobook on the other hand was intended for use in Oasis and will presumably still work and have a use.