Usage of "37i m"

What possibly could the sign “i” in “37i m” mean? I guess it’s a unit of measure.

Are we in the territory of B-splines and recurrence relations? :shock: Or telescope and camera accessories, maybe? :?

I think it deals with B-splines and recurrence.

Perhaps you could provide the specific example of the sentence where you found the term? That might help us determine what it means.