Template:Ifsubst
Usage
Meta template that returns the first parameter if evaluated during substitution, and the second parameter if evaluated during transclusion.
Note that this template must be used in safesubst mode to work properly:
{{ safesubst:<noinclude/>ifsubst| yes | no }}
The |demo= parameter can be used for testing the template. Set |demo=yes to always display the yes text, |demo=no to always display the no text, or |demo={{{demo|}}} to pass through the value from the parent template.