From Rosetta Code

Usage: =={{header|language name}}==

This template is intended to be used for the header of a programming language solution. The language's category is added to the task page and the Semantic MediaWiki property Implemented in language is set.

The special cases C# and F# are handled properly; one can use either C#, C sharp or C Sharp as the language name (similar for F#).

This is a template. There are many others. See Category:RCTemplates for a complete list of templates.