Template:MC/Void/doc

Template:Documentation header This template does nothing visually. Technically, it throws away its parameters and outputs the null string.

It is useful for programming advanced templates, and is often used within a template to the right of an equals sign. It may also be used in a template to disambiguate parsing of braces.

It can also be used to temporarily disable code. Unlike "commenting out" with <!-- -->, it nests. This means that {{void|foo {{void|bar}} baz}} is valid, whereas <!-- foo <!-- bar --> baz --> will produce baz -->.

It provides a particularly concise way of temporarily disabling templates, by prefixing the template name with void|, making the template name becomes the (ignored) first unnamed parameter. For example, suppose you have a page {{wip}} for several days, and wish to change that to {{in use}} during active editing sessions. Rather than delete the unused template, you can leave both templates in the wikitext and change from {{void|wip|...}}{{in use|...}} to {{wip|...}}{{void|in use|...}}.

A deeper no-op is {{subst:void|foobar}}. It disappears completely upon saving.