Absolutely proper. Why?
To start with MKV is not a format but a container. A bucket in which you can place videos of any encoding you can dream up into.
What I find is folk that want this to work but also do not want to know how it works or what a MKV is or what video encoding is.
They'll write they looked all over but the awful truth is that the explanation is technical and not one person or web site will convey the needed details to get a new to this person up to speed.