To create categories on your registry, log in to your account and click Edit located at the top of your gift list to Create categories. Once your categories have been created, refresh your page and click the pencil icon for each item you want to categorize and select the appropriate category from the Edit panel that opens.
When you add a new item to your registry, you have the option of selecting a category for that item so that it will automatically appear under the chosen category on your registry. In the Add to MyRegistry panel window, simply choose the desired category from the Category section before adding the item to your registry. If you choose to keep items in the Private category, your guests will not be able to view them.