Field registry

SP/1 defines a closed registry of twelve field keys. Grants MUST reference registry keys exactly; implementations MUST NOT invent ad-hoc keys inside the protocol surface (extension fields belong in a future registry revision — see governance).

Registry

Key	Label	Notes
first_name	First name
last_name	Last name
email	Email	Lowercased before hashing/blind-indexing
phone	Phone
address_line1	Address line 1
address_line2	Address line 2
city	City
state	State / region	Two-letter USPS code for US addresses
zip	ZIP / postal code
country	Country	Short country code preferred (e.g. US)
company	Company
date_of_birth	Date of birth	Opt-in only; MUST NOT be required by a recipient

Scope groups

Groups exist for consent presentation and update propagation; they expand to registry keys on the wire:

Group	Expands to
address	address_line1, address_line2, city, state, zip, country

Rules

• Values are UTF-8 strings, trimmed, 1–500 chars.
• A grant’s fields array MUST be non-empty and MUST be a subset of the registry. Order is not significant on the wire, but fingerprint inputs use the array as-granted (see fingerprints).
• Recipients MUST NOT receive, cache, or infer fields outside the granted set.
• Subject updates to a field propagate to every active share whose scope includes that field (consumer.updated.* events) — and to no other share.