How do I delete To Do Categories that I added?

Hello,How do I delete Categories/Keywords that I added when creating To Dos.

I have lots of old Keywords that I don’t need anymore and they still being displaid in the Categories field. How do I remove them? I have removed all the To Do docs with those categories, deleted the cache.NDK and compacted the db. But the categories remain.

Many thanks in advance.

Subject: I found the answer…

Tools → Preferences → Calendar & To Doand the user categories are shown and can be deleted from here.