Go to Lists and click Categories. Click on the Add a New Category
button.
On the next page, enter the name of the category in the field for
Description. Your subscribers will see this name if you use the Subscriber
Update page and the categories are viewable (not Private).
Tick the Active checkbox if you want to begin using this category
now and begin to assign addresses to this category.
Tick the Private checkbox if this is a category that you do not
want your subscribers to see on the Subscriber Update page. (See our KB article
on the Subscriber Change Link for more information.)
Click Save Changes to add the new category.
After saving the changes, a message in red will appear that
confirms your new category was added. To return to the list of categories,
click Return to the Category List. To add another category click Add Another
Category.