Quote: When you say "Old Russian" do you mean "Old Church Slavonic"?
I'm going by memory, but I believe Old Church Slavonic was 9th and 10th centuries? Old Russian was medieval... about 11th to 14th centuries.
So when I said Old Russian, I didn't mean Old Church Slavonic, I meant Old Russian. I think some linguists prefer the term Rusian, but I see Old Russian so frequently, that's the one I used.
Maybe it shows up in Old Church Slavonic manuscripts, but I haven't looked at those. I have looked at Old Russian manuscripts.
By the way, I know very little about Old Russian. I can only read a tiny bit of Russian (I've only had one very short course in Russian). I just know that the VMS rare char shows up with moderate frequency in Coptic scripts and occasional frequency in Old Russian scripts and in Latin scientific manuscripts.