Categories can be assigned to items. They are displayed in the header panel of the Content Pane or in the property page for the item. They can also be used as criteria for searches. You could, for example, define a category for each project that you are working on, and could then filter all of your tasks (to-do items) by category to get a project-specific view of your work list.
Open the properties for an item.
In the General tab activate the drop down menu for Categories.
Check the box next to each category you wish to assign to the item. Click on a checked box to remove a category from an element.
Open the properties for an item or task.
In the General tab click on the [Categories] button next to the category list field.
In the New Category text field enter the name of the new category you wish to create and click on the [Add] button. To remove a category select it from the list and click the [Delete] button.
Click [OK] to exit the category edit dialog box.
Click [OK] to exit the properties dialog box.
To search for items that have been assigned a category.
Open the advanced search.
From the Field drop down menu select any set of fields and then category
Enter an appropriate condition.
Enter the name of a category
Execute the search