I have just tried to create a tag, and was informed I needed at least 300 rep. I can't find any reference to this, the FAQ lists my next goal as 1000 (my current rep is 182). Are there any more hidden privileges because 1000 seems a very long way away?
Click on the "badges" tab in the upper-right-hand corner:
Then click to the "privileges" page:
This brings you to the FAQ. Scroll down until you see this box:
There you go!