If the PC routine is to be available to users in all address spaces, code running in the service provider's address space must issue the macros. The following figure lists the macros that must be issued. For a space switch routine, refer to the left column. For a non-space switch routine, refer to the right column. Several of the macros shown in the figure must be issued in a specific sequence. Therefore, IBM® recommends that the service provider issue the macros in the sequence listed.