Kind
Kind is a reserved, prim-level metadatum whose authored value is a simple string token, but whose interpretation is backed by an extensible hierarchical typing-system managed by the pxr.Kind.KindRegistry singleton.
USD Terms and Concepts — Universal Scene Description 22.08 documentation
Kinds are just TfToken symbols, but the KindRegistry allows for organizing kinds into taxonomies of related/refined concepts...
Universal Scene Description: Kind : Extensible Categorization
pxr.Kind.KindRegistry singleton に登録されている文字列 (TfToken) のこと
専用の pxr.Kind module が API
以下の事前定義された Kind の他にユーザーが自由に拡張可能
事前定義された Kinds
Model
Group (Kind)
Assembly
Component (USD)
Subcomponent