The templates P1, P2 and P3 simply return the first, second and third unnamed input parameter respectively. For example:

• foo returns foo
• bar returns bar
• baz returns baz

These templates can be used inside other templates as an alternative to the #switch parser function, to switch between outputs based on whether the input is "1", "2" or "3":

• {{P{{{1}}}|output if 1|output if 2|output if 3}}

Using {{#switch}}, this syntax is equivalent to

• {{{#switch:{{{1}}}|1=output if 1|2=output if 2|3=output if 3}}

except that the parser function strips whitespace between parameters whereas the templates don't.