Template talk:If not pagename

For each pagename you'd like to test against, you need to create a new template. For example, if you want to be able to use

{{If pagename|Sandbox|We're on the Sandbox, no place else.}}

you need to create a page Template:CallSandbox, with content

{{{{{Sandbox}}}|{{{1}}}|{{{2}}}|{{{3}}}}}

See also Template:If pagename, for which the same note applies.