Obtaining and passing ALETs for hiperspaces

To allow other programs to share hiperspaces, a program passes the ALET of the hiperspace to other programs. Because ALETs index into specific access lists, a program can pass:

An ALET that indexes into an entry on a DU-AL if the passing program and the receiving code are represented by the same TCB
An ALET that indexes into an entry on a DU-AL if the passing program attached the receiving program (using the ALCOPY parameter on ATTACH or ATTACHX) and passed the entry for the hiperspace on the DU-AL
An ALET that indexes into the PASN-AL if the ALET indexes into the PASN-AL of the receiving program.

Generally, when two programs in two address spaces share the data in the same hiperspace, the programs must both use ALESERV to add entries to their access lists.