Recently, Wikia announced that they were going to upgrade the MediaWiki software that runs all of their wikis. They have a lot of testing to do to make sure everything they've customized works with the new version. Some of the updates include making sure the code is HTML5-compliant. As such, the really old HTML commands wouldn't work any more or act weird.
When they announced this, the plan was for us to research the updates and prepare a guide so that we know what we have to do different. Basically, if we used old command A, we would have to replace it with newer command B. From the way they were talking, we thought we had about a month before we would be affected.
Nope. We found out last night that the Phineas and Ferb Wiki has already been upgraded to the new software. Since the upgrade process was biggest wikis to the smallest, that means we're amongst the largest wikis that deal with TV shows. So yea for that.
The conversion guide hasn't been started yet, so this blog is just to let everyone know that if you make an edit on a page and something else suddenly doesn't look right, it's a side-effect of the change to HTML5. It will usually be a table or a template that is affected.
Right now the plan is to fix what breaks, then we can look at an overhaul of our own to make things a bit more streamlined and more efficient.
When we get more information, we will let you know.