Which locks and other gizmos can we use on our folders?

[F. Allin Kahrl]

I realize this may get moved to Knife Law but I thought you guys might have more experience with this than the folks over there, so...

There are a lot of novel locks and one-hand opening mechanisms out there, some of which are protected by patents and defended by their owners, others which aren't. Which ones can we use, which ones can't we, and what can you think of that's not on this list?

Locks
traditional lockback - obviously public domain
liner lock
frame lock
Axis Lock - I'm aware that BM is defending this one like a momma bear
Ball Bearing Lock - I assume Spyderco is being as diligent with this one
Gerber/LoneWolf Paul lock mechanism - I'm guessing this one is patented
Rollock
Matt-Lock - is that the correct name?
One-Hand lock used by AGRussel
French ring lock

Opening doodads
thumb stud
thumb disc
round hole - oops. I mean Round Hole™
torsion bar assist​

What'd I forget, and what do you know about the availability of these to custom makers?

 

[IronKnuckles]

As to the locks, I saw in Blade magazine a cable locking mechanism (I wanna say CRKT? I'll look again later)