The Keyword nodelet displays the several most commonly added ("top") keywords. It is o.k. to add a keyword again; in effect, this "votes" for the keyword.
In the text box, you can type in one or more space-separated keywords. Keywords cannot contain spaces.
Janitors have the ability to delete keywords from the list. For them, the Keywords Nodelet includes checkboxes next to each keyword. To delete a keyword, check the corresponding checkbox and click 'Submit'.