If exit routine processing is enabled, and the currently defined exit routine exists, then when one of the following events occurs, the exit routine is invoked to determine whether or not to notify the operator:

• IDF is preparing to present its first screen display
• A breakpoint is reached
• The target program branches outside of its memory limits
• A condition exists which puts IDF at risk of losing control
• A program check occurs
• The target program experiences a CMS, z/OS, or z/VSE ABEND
• The target program has completed and returned control to IDF
• A single-step operation has just completed
• On CMS only:
  • SVC tracing is in effect and an SVC is reached
  • A monitored storage location is modified
  • A monitored register is modified