Rhino 7 documentation says: The SubDDisplayToggle command switches the appearance of all SubD objects between smooth and flat modes. source: https://docs.mcneel.com/rhino/7/help/en-us/commands/subddisplaytoggle.htm
On the other hand, Brian James and Kyle Houchens claim that the flat mode is called box mode. source:
I call it flat mode. What is your opinion?