By use of the protocol relative urls, one is able to create urls that circumvent the blacklist
eg. [//skiptest.info skiptest]] will form a clickable functional url
I have tested at meta against the global spamlist, and at local wiki against the Mediawiki:Spam-blacklist at that wiki, both times success (if you call that success <urk>)
Version: 1.18.x
Severity: major