From Facebook Developer Wiki

It could have been great if an implementation example exists.

I am able to add tags, but something is wrong. The x coordinate is correct, but the y coordinate doesn't seem to take as my tags are always at the top of the image

Please file a bug and include the code you're using for adding tags and your app ID. Thanks, Pete (563683308 13:52, 18 September 2009 (PDT))