It was added on 1 April 2014, and revised on 2 April 2014.
We hope you enjoyed the April Fools' Day pranks this year! The forums and the game should now be back to normal.
The RuneScape Team
RuneScape Wiki: Below is the original news post.
Unfortunately, due to a technical glitch, a private Jagex employee forum has become visible within our player forums.
Whilst we work to remove the threads, and locate the cause of the issue, we would ask that you do not read the posts.
If you have already stumbled across the threads accidentally we apologise for any offence that may have been caused. These comments were intended to be private conversations between Jagex employees only.
We have also received reports of some in-game issues relating to Firemaking. If you experience anything unusual whilst skilling in Firemaking please report your issues to Player Support here.
The RuneScape Team