Posta di Bicorno Instabile - Two Horned Ward

This is the Posta do Bicorno that stays much public that always stays with the point in the middle of the road. And that which Posta Longa can do this can do. And similarly I say this of Posta di Fenestra and of Posta Frontale.

After working with some of the German longsword guys, we have an idea on how Bicorno might actually work, and what it's used for. We think it's a defensive ward that you come to when covering a blow. It seems to work against sottani or fendente blows primarily.

Then there's this article from Guy Windsor, that makes even more sense.