This template checks if the source page upon which the translation is based has changed, and displays a warning message if so.
Put the following at the top of your translated page:
{{AutoOldtrans
|Base Page=<page the translation was based on>
|Base Revision=<revision number of the Base Page>
|Language Code=<code of the language of the translation>
|Hide=<optional parameter to hide the message, used for Main Page translations>
}}
Revision number used should be the version of the original page that the translation is most up to date with. When the original page gets edited, a tag will automatically show up on the translation pages. You can find the current revision number of a page by looking at the "oldid" section of the "Permanent link" link in the toolbox section of the sidebar.
Outdated translations will automatically enter Category:Outdated translations.
See also: IMSLP:Internationalization.
