Octothorn vs. Octothorpe: What's the Difference?

Octothorn and Octothorpe Definitions
Octothorn
(rare) octothorpe, the symbol #.
Octothorpe
The symbol (#).
Octothorpe
The hash or square symbol (#), used mainly in telephony and computing.
Octothorpe
On a push-button telephone. Rumor at the telephone company is that a man named Charles B. Octothorp, wanting to make his name famous, would approach anyone with a Touch-Tone ’phone, stop, and say admiringly, “That’s a mighty handsome octothorp you have there.”