o  When an executable image consisting of several object modules
       is linked, only one object module should be terminated by an
       .END directive that specifies a transfer address. All other
       object modules should be terminated by .END directives that
       do not specify a transfer address. If an executable image
       contains either no transfer address or more than one transfer
       address, the linker displays an error message.

    o  For more information, see the .PROCEDURE_DESCRIPTOR directive.