Please read carefully:

Below is a drop down list with all the entries currently listed for Harry Potter and the Half-Blood Prince (mistakes and trivia, in case of cross-over - don't worry about repeated corrections). You'll only be able to see part of the entry, but hopefully that should be enough to pick it out (if not, click here to see the normal listing). Simply pick the option referring to the same thing as the entry above and click "continue".

Choose the similar mistake