I mentioned in an earlier post that Koshiki no Kata illustrates two levels of knowledge - Omote (superficial) and Ura (profound). But actually there is a third level of knowledge that is illustrated in the kata - a set of techniques or behaviors that is assumed to exist before Omote can happen. Uke's attacking actions.
Throughout Koshiki no Kata, uke attacks using a handful of actions that must have been commonplace on the feudal battlefields that spawned jujitsu schools such as Kito Ryu...
- hipthrows similar to tsurigoshi - bodily lifting an opponent and smashing them to the ground
- grabbing for an opponent's weapon if yours is broken or lost
- reaching/grasping/thrusting at the opponent's exposed face or throat
- an arm-locking shoulder/hip throw or scooping throw - again bodily lifting and dropping the opponent
- pushing the opponent facefirst into the mud
- trying to bodily bear the opponent down or tackle him
- rear bearhug pinning the opponent's arms so your buddies can dispatch him.
If you were tasked with training a bunch of noobies a handful of tricks that might save them (or at least make them more effective) in the event they were disarmed on the battlefield, the above would be a pretty good short list.
If you were to design a school of jujitsu with different levels of attainment, then the above would make a pretty good first level of skills, followed by common counters to the above (Omote) and perhaps a third level of advanced flow and understanding (Ura).
So, the knowledge underlying Koshiki is actually divided into three levels - The above pre-requisites for uke, the Omote, and the Ura.