Keyword catalog

Descriptors are built from keywords. Each keyword acts at a fixed stage of the evaluation pipeline. This catalog groups them by stage:

Group	Keywords	Stage
Locate	source target input output	locate
Structure	mapping each	structure
Registry	$id $ref $extend description	registry
Variants	array form, first last all concat	locate/shape
Shape	switch find init constant template transform random unique	shape
Validate	type minimum maximum multipleOf minLength maxLength enum pattern required	validate
Finalize	default as regexp_i	finalize
Plugins	plugin keys, pointer, stdout	plugins

Tiers: Core keywords are required of every implementation. Extended keywords are optional, exact if present. Experimental keywords are unstable. See Conformance.

Unknown descriptor keys that name no registered plugin have no behavior.