Ifsubst/doc

This template is used on 500,000+ pages. To avoid large-scale disruption and unnecessary server load, any changes to this template should first be tested in the template's /sandbox or /testcases subpages, or in your own user space. The tested changes can then be added in one single edit to the template. Please consider discussing any changes on the talk page before implementing them.

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:}}}ifsubst| yes | no }}

• {{require subst}}: Prints an error unless substituted.
  • {{subst check top}}、{{subst check bottom}}: Same purpose, but used as a pair.
  • {{subst only}}: For the doc of the above templates; prints a message asking for it be substituted.
  • {{nosubst}}: The reverse of {{subst only}}. For the doc of templates which should not be substituted; prints a message asking for it not to be substituted.
• {{issubst}}: Returns "yes" if substituted.
• {{ifsubst}}: Forks if substituted or not.