Content evolves independently from translations. Visitors of the website need to be aware that more information is available elsewhere if the translation is not complete. This page lists various information that could be presented to the users.
Wether the translation is up to date or not. In the case the translation is not up to date, the amount of time it has been out of date could also be indicated.
Measure of translation progress
It is useful for the users of a wiki translation system to be able to know how much a given translation is up-to-date with respect to other versions which may comprise modifications that have not propagated. See: Measuring translation progress in the CLWE Project
Critical out of date
Not only the current translation is out of date, it is likely to contain critical errors that were introduced by the previous versions of the source page. The correction is now included in source and current page can no longer be relied on.
A list of up to date translations that could be used by the user to obtain the content.
These translations could be bound to user preferences to reduce the length of the list and remove irrelevant translations. Anonymous users could not benefit from this. Instead, request headers could be used to sort the translations properly.
Estimated translation date
In controlled contexts, it may be possible to indicate when the page is expected to be translated. This information could come from direct user entry or site policy (ex: translation within 2 weeks from original change).