Beyond the Git history, is there any write-up of the different capability designs you've gone with?

I'm interested in implementing a safe low-level language with less static information around than C has (e.g. no static pointer-int distinction), but I'd rather keep around the ability to restrict capabilities to only refer to subobjects than have the same compatibility guarantees Invisicaps provide, so I was hoping to look into Monocaps (or maybe another design, if there's one that might fit better).