Merging Categories in Outlook 2007 & 2010

Using Outlook Categories to tag emails and calendar items for things such as projects I'm working on, groups I am involved with, and script snippets I'm emailed is an extremely useful habit. It enables me to use Search Folders to their fullest, it helps me use regular search more effectively, and it makes my calendar go from a group of rectangles and text to a color-coded plan for the day. However, after over-enthusiastically using the Categories feature for some time now, I found I had begun creating, as Merlin Mann would say, "the most crazy, byzantine, taxonomically complete system that you can think of...'

Categories such as '_SQL' & 'SQL Scripts' or '_GP,' 'GP 9,' & 'GP 10' started to appear in my list. In the beginning, separating all these seemed like a good idea, but I soon found that there is a trade-off between how specific my categories are, the time it takes to categorize a message, and how useful my searches are. If I have categories that are too specific, it takes me longer to correctly categorize a single message, and longer to select all the categories I might need for a search. I wanted to simplify things and combine categories. During the process of tuning my category choices, I stumbled upon this feature, which as far as my Google searches reveal, is almost completely undocumented.

Now, after a long-winded introduction, here is how to merge Outlook categories for Outlook 2007 and Outlook 2010!
For this example I will merge 'SQL Scripts' and '_SQL' to become '_SQL'
(The instructions below show pictures for Outlook 2010, but the steps are the same in Outlook 2007)

1. Open All Categories from the Categorize menu.
   
   
2. Select the category that you wish to be renamed and merged into another category and click Rename.
   
3. Rename the category to the category you wish to merge it with, then hit Enter. (I renamed 'SQL Scripts' to '_SQL')
4. Click Yes at the dialog box.
   
5. Success!

My results from this are below:
Before:

After:

Note that the color of 'SQL Scripts' was given to '_SQL.'

Hopefully these instructions will save some time and help you reduce the number of crazy categories you may have. Leave a comment if this was helpful!