OfficeTalk lets you define a set of categories which may be used to classify your project tasks. To mark a task as belonging to a particular category, do the following:
Bring up the Project Task property sheet by double clicking on the relevant task.
Select the Categories page. The Categories page will display a list of project categories in the bottom window. Each category has a check box to the left of the description.
Select one or more check boxes representing the classification of the task into the relevant categories.
Press OK to save your changes.
You may add your own private categories by typing the name of the category into the Categories window in the Categories page and pressing the Update button. The new category will appear, checked, in the bottom window. Press OK to save your changes.
For more information on Categories, see Using Categories.