Category:Mars Exploration Rover Mission

You can create a new category with this button. Leave the word Category: in place and add the name of your new category after it.

<inputbox> type=create default=Category: buttonlabel=Create Category </inputbox>

You will still need to enter [[Category:Mars Exploration Rover Mission]] in your new category to have it show up in this list. If you wish to include this template, then add the line {{CreateCat}} also.

In the Subcategories list, clicking on a [rotating triangle] will expand the category to show subcategories if any exist.