I'm not exactly sure how user submitted categories work but I do not see option to require approval for new user submitted category nor the option to turn off user submitted categories (I tested via photos)
I tested as regular user to submit custom category. It does not show in the admin categories pending approval as it's empty.
I also noticed that user submitted categories creates a category link under Main Photos Info box and takes me to an URL that looks like this: mysite.com/testb6/m/photos/browse/category/photos category test suggestion
See the spaces in the user submitted category? Shouldnt there be something like dashes or underscores instead of spaces? Yes?
Am using beta 6 dolphin and firefox 3.5.3