I wonder how many built-in caveats capabilities or "implementation references" we could have to showcase all the GCP capabilities https://cdn.discordapp.com/attachments/844600078948630559/1158892819734351902/Screenshot_2023-10-03_at_6.21.31_PM.png?ex=651de68b&is=651c950b&hm=08f88712aed7763b9cfdac177d94ca44b9a78615ab6dc7aa4acb57d94ae70686&

what do you mean with "built-in caveat capabilities". Are you thinking of caveats that come as part of every schema out of the box so you don't have to implement them? If you are thinking about language functions, SpiceDB caveats uses CEL expression language, so there is a lot of useful built in operands and functions.