An hexadecimal string of 24 characters

The Permanent Patient Identifier (Identifiant Permanent du Patient, or IPP). Deprecated: use patientIds instead. Always holds the last written identifier value, whichever client wrote it. Per-authority values are available in patientIds. When an assigning authority is configured on the client's establishment in the ROFIM portal, legacy ipp values written through this API are backfilled as patientIds entries under that authority.