Sometimes, e.g. when a page has already been completely translated into a few languages, as a translation administrator one would like to send out a translation notification for all remaining languages, without bothering translators about the already completed languages.
I could see basically two possibilities to integrate this into the UI at Special:NotifyTranslators:
- Add a checkbox like "Don't notify about languages which are already 100% translated" (I assume that this isn't already the default behavior)
- Add the option to enter a list of excluded languages (e.g. "Notify all languages except these:", this could be combined with the existing "leave blank to notify for all languages")
This second option would be more flexible and also allow for situations where a translation is already being prepared elsewhere to be imported later. But it might be a bit more confusing.