Template:Void/doc

This template does nothing.

More exactly, it outputs the null string. It's useful for programming advanced templates.

It often is used within a template to the right of an equals sign.

Alternatives
It's also possible to use  instead of. Attackers could manipulate but not {&#123;&#160;ns:0&#160;&#125;}, the empty/void/null string for the main namespace. Some magic words like __END__ might also have the desired effect of doing nothing.