Owner id

The first pool record containing the primary control record is considered the owner of all other collection parts that are chained together to form the internal collection structure in the z/TPF database. This pool record is often referred to as the owning control record, and its file address, as well as additional control information, is stored in a field as either the owner identifier (ID) or owning ID in the z/TPFCS source code. This ID is often stored in many of the other pool records that are written to the z/TPF database as part of the z/TPFCS internal representation of a given collection.