CXF Files

The wiki states one feature of LibreCAD as:
Opening and saving .dxf,.cxf,and.lff
I understand .dxf as (AutoCAD) drawing interchange format, and .lff as LibreCAD's font format but what is .cxf? Is it color exchange format and is it, therefore the basis for the color palette used in LibreCAD?

CXF stands for CAM Expert Font.
I had to look in source code, because I wasn't aware of if.
Maybe that's a relic from QCAD, I haven't heard of CXF fonts yet.

Armin

Thanks Armin.
I was sure if I didn't ask here then one of my students would ask me.
Cheers
Paul