Steps to replicate the issue (include links if applicable):

• Add a category (as opposed to a regular page in the main namespace) to [[:nl:WP:TBP]] as per the instructions

What happens?:

• the bot runs at the scheduled time daily and sees the category is mentioned on TBP, so it informs the creator of the caegory on his or her talk page

What should have happened instead?:

• because WP:TBP is not for categories, the category should simply have been ignored, so the cat's creator wouldn't be notified.

As a result of the notification not escaping the category with a colon the talk page was miscategorised. However this would not have happened if the category would have been skipped in the first place.