To apply a rubric comment to a submission:
Highlight code to create a new comment
While the new comment is open for editing, click a rubric item on the bottom left of the Code Console
If you want to apply a rubric comment to an existing comment, you must first click the comment to enable editing. Note that applying a rubric comment will remove any manually placed deduction you added to the comment.
You can remove a rubric comment by clicking the "x" next to the rubric comment's text. Again, the comment must be open for editing before you can remove its rubric comment.