Return to the course front page. Click on Settings in the Administration block.

Click on Number of weeks/topics list and add another topic.

Scroll down to the bottom of the page and press the Save changes button.

Edit the new topic's summary to tell your colleagues (and the inspector) that this topic is specifically for teacher documentation and nothing else.

Hide the topic from your students by clicking on the open eye on the right-hand side. The eye closes to indicate that the topic is hidden:

6. You're done!