For each PC routine, the service provider issues the ETDEF macro to define the PC routine's name or entry point and its environment. A PC routine's environment refers to whether the routine runs in supervisor state or problem state, the value of the routine's authorization key mask, whether the routine causes a space switch, and so forth. After defining the PC routine's environment, the service provider issues ETCRE to create an entry table. The service provider's home address space owns the entry table.

The entry table contains one entry for each PC routine. Each entry contains the operating environment definition created by ETDEF. Before a user can invoke a PC routine, the service provider must connect the entry table to the linkage table of the user's address space.