Here is a list of all documented concepts with brief descriptions:

Nnative	Architecture-tagged vectors, register packs and supporting value types. Native arithmetic follows its architecture tag and instruction-set preconditions. Common utilities do not select or admit a runtime CPU profile
Rarch	A feature enum or an ISA value from one architecture family
Rnot_one_of	`N` is not one of the `candidates`
Rnot_one_of_t	Type `T` is not one of the `candidates`
Rone_of	`N` is one of the `candidates`
Rone_of_t	Type `T` is one of the `candidates`
Rtrivially_destructible
Rwaiter	Some way to wait for a value to change
Nwide
Rpack	A homogeneous batch stored in a standard array