What is Person Identification Data (PID)?

PID is the foundation. The member state issues it, and other issuers lean on it when binding their own attestations to a person. It is also issued in both mandated formats at once, mdoc and SD-JWT VC, so the same person carries two technical copies of the same data.

The mandatory set is much smaller than people expect. Only family_name, given_name and birth_date must be present on every PID. Optional attributes an issuer may add include family_name_birth, given_name_birth, birth_place, the resident_ address elements, gender, nationality, and the derived age elements age_over_18, age_over_NN, age_in_years and age_birth_year. Metadata is a separate group, where issuance_date, expiry_date, issuing_authority and issuing_country are mandatory and document_number is not.

Those derived age attributes matter more than they look. Asking for age_over_18 instead of birth_date means you learn a boolean rather than a date, which is a much smaller thing to justify, transmit and store. The catch is that age_over_18 is optional, so some PIDs will not carry it and your query needs a birth_date branch you then discard immediately.