Where is the 'class' field in the FvwmIconMan source code?

I think I’m a little over my head when perusing the source code for FvwmIconMan.

I’m interested in cropping the ‘class’ field down to the first 3 characters. It helps to identify the program without large program names taking up the visible area of the button. I know basic c and can edit the field. I just need to know which one to edit.

Can anybody help shed some light on this, please?

Look at xmanager.c:make_display_string()

– Thomas Adam