Board Thread:General Coding Help/@comment-4224349-20151029202124/@comment-1757994-20151029210534

For example, wrapping the template in the above condition stops it from displaying in any namespace except Main: (0). So you can't stop users from using the template, but you can stop the template from producing any output. If you want to allow multiple namespaces, you can use a switch instead of an if.

Of course, nothing stops them from making their own template, either.