RACF® running with enhanced
program security, BPX.DAEMON defined, and BPX.MAINCHECK defined. You
can use BPX.MAINCHECK for any privileged z/OS UNIX application
that requires a program controlled environment, because the application
uses a privileged z/OS UNIX service
that requires one. An example is the __passwd() service, which is
used by applications such as telnet and rlogin.