Temporary authorization granted by principal accrediting authority (PAA) or authorizing official (AO) for an information system to process information based on preliminary results of a security evaluation of the system.
Sources:
CNSSI 4009-2015
under interim approval to operate
Interim Authorization to Operate; issued by a DAO to an issuer who is not satisfactorily performing PIV Card and/or Derived PIV Credential specified services (e.g., identity proofing/registration (if applicable)), card/token production, activation/issuance and maintenance).
Sources:
NIST SP 800-79-2
under IATO