I suggest you do not use legally defined terms.
Create the code. Let the user, company or jurisdicrion figure out how to define it.
Discussion
I hear ya. Just trying to front run the legal definitions. They catch up, eventually, whether private law (contracts) or public law (legislation).
The big insight for me was the clarification between custodianship and trusteeship
Been down this road before. Just focusing on the wording technology.