A threshold of unmodified text is defined in T190279 to encourage users to review low quality translations. Warnings will be shown for paragraphs that having a reasonable length have not been edited enough. However, these warnings do not prevent users from publishing.
In order to facilitate the work of the community, those translations will be included into a "unreviewed translation" category.
A translation will be included in the category when any of their paragraphs meets the criteria for showing the unmodified text warning. Even if the user marked all the warnings as "resolved". This category is intended enable communities to review the translations that have not been completely reviewed.
Previously we were considering to use a #unreviewed translation edit tag, but a category was preferred since it fits better the workflow of finding+fixing issues.