|Warning - This version has not been released yet. This feature may be modified or removed before the final release.|
Adds a notice that the feature is part of a future version of MediaWiki, and places the page in Category:Future, if no version is supplied, or
[[Category:Due in vX]] if it is (where X is the version number).
nocat parameter is specified, the page will not be categorized.
This can be useful for extension pages that wish to use this template.