I recently had a client ask if additional categories could be added to the choice list in the SharePoint 2010 Calendar Web Part. These categories are in the pick list when you create a new calendar item from the SharePoint interface.
This is how to change the categories:
1. Go to the calendar web part from the browser.
2. Under the Calendar Tools tab, click the Calendar tab.
3. Choose List Settings.
4. Scroll down to the Columns heading.
5. Click Category.
6. Under the Additional Column Settings heading, there is a text box with the categories, and above the box reads: “Type each choice on a separate line.”
7. Add or remove categories, then click OK.