Must lock with enough pressure to positively attach any device or optical instrument to a rail without movement, static or dynamic forces not withstanding.
The rail must not experience any deformation due to user error. This must include synthetic (plastic/polymer/composite) rail systems.
Auto Index capability. The device must also index parallel to the bore. The unit must always repeat the forward shift (recoil forces direction of influence) not only to maximize zero repeatability, but to take this step of installation out of the users initial mounting sequence. Index must be redundant.
Unit must not shoot loose due to improper mounting or a mechanical bottoming out.
The system must incorprate a safety that prevents the lever from being accidentally opened. The safety must be able to be manipulated in conjunction with the lever rotation, so that only one hand is required to open it.
The unit will utilize constant force to ensure required pressure in all conditions. The force must be substantial to prevent any shift forward/aft left/right.
The pressure must be applied in a linear direction centered in the main body to prevent cocking of the mount.
It must be easy to manipulate by gloved or fatigued hands.
It must be extremely robust, and withstand shock and impact to the system housing.
There were others, but by listing them we would compromise our trade secrets.