What's this method called

[Markus Keller]

I should know this but can't seem to think of what this structural installation is called. I know one of you will come up with it.
Thanks, Markus

[James Duffin]

mortise and tenon joints?

[wayne soper]

That's somewhere between post and beam and timber bracing in a mineshaft. Did someones sister live on the second floor?

[Bob Knauff]

Looks like a form of post-and-beam construction used in old barns.

[Tom Thompson]

Knee bracing