Board Thread:News and Announcements (ADMINS ONLY)/@comment-26897006-20141212111550/@comment-26501002-20150206175617

It doesn't say that is a requirement -- hence the "should" part. It is just one of those recommendations that Wikia always puts out there, such as some like "don't lock pages unless they are high traffic or high vandalism pages". They don't come through and hand out warning or alterations. Only a recommendation to make Wikia viewer-friendly.