C slash in mirror? What do you mean? I think you're clear. You mean the opening to the letter C is normally on the right, and "in mirror" the opening is on the left? I've never seen it with a slash.
Somehow I believe to have seen it in Schütz as proportio quadrupla...B.
To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
