Working with Contacts
If you have a large contact list, use Categories to create subsets that you can sort and group by. You can even create custom categories.
Open a contact item. Enter a category or categories in the field at the bottom of the form (use commas to separate categories).
To pick categories from a list, click the Categories button at the bottom of the form. To create a custom category, click the Master Category List button. Type in the custom category and click Add.