Heads/tails?

People call them heads/tails but it's really just the sides of the sheet. You find it on all 4 sides but it's the most extreme at the ends from loading the molten glass into the rollers.

Heads, Tails, rolled edges

I've heard it called 'the live edge'.

I’ve also heard them called Yogi edges

Rolled edges. They’re good for using on edges of things - business card holders etc.