An individual applying for a PIV Card/credential. The applicant may be a current or prospective Federal hire, a Federal employee, a government affiliate, or a contractor.
The subscriber is sometimes also called an "applicant" after applying to a certification authority for a certificate, but before the certificate issuance procedure is completed.
NIST SP 800-32
A party undergoing the processes of registration and identity proofing.
NIST SP 800-63-2
An individual applying for a PIV Card.
NIST SP 800-79-2