#0 - May 19, 2009, 9:24 a.m.
Blizzard Post
This was posted by Ghostcrawler and we have seen a thread or two about it here. Sticking the same information for visibility.
Q u o t e:
There is a bug with this glyph that makes it more effective than intended. The current glyph is basically for PvP situations because it gives you an IBF as if you had a lot of defense, which you probably don't in PvP. It was not intended as a tanking glyph. However there is a bug which makes the glyph better than it should be for PvE DK tanks. We wanted to let you know that we will be hotfixing that bug. If you were considering running out to buy the glyph for tanking purposes you should probably reconsider.

If you don't have the IBF glyph now, this change won't affect you. If you are a PvP DK with this glyph, the change probably won't affect you.

The glyph was supposed to give you a stronger IBF as if you had high defense. This made it more of a PVP glyph since tanking DKs already should have high defense. Therefore the glyph was supposed to do nothing for them.

The bug was that it did increase their IBF even at high defense. This turned the glyph from a PvP glyph into a mandatory tanking glyph, and probably an overpowered one at that. I believe the hotfix has gone live already.
http://forums.worldofwarcraft.com/thread.html?topicId=17163477544&sid=1