I'm currently studying the Georgian language and it has quite a few interesting properties not common in more well known languages.
One property of the verb is called "version", "version markers" or "versioners". And it is used to describe the role of a vowel in the agglutinative verb template which relates to how polypersonalism works.
From the Wikipedia article Georgian verb paradigm:
Versions. The versioners in Georgian establish the language's polypersonalism.
The sister languages of Georgian (Laz, Mingrelian, and Svan) also use the version concept.
But what I'm wondering with this question is whether the concept of version is also used in any other languages. Kartvelian isn't known to be related to any other language families, but it is in a Sprachbund with other Caucasian languages and often terms in linguistics and grammar are borrowed by people describing other languages, especially ones in a neighbouring area or studied by the same people.