Tracepoints can be user defined or predefined. User-defined
    tracepoints are explicitly set with the SET TRACE command.
    Predefined tracepoints, which depend on the type of program you
    are debugging (for example, Ada or multiprocess), are established
    automatically when you start the debugger. Use the SHOW TRACE
    command to identify all tracepoints that are currently set. Any
    predefined tracepoints are identified as such.

    User-defined and predefined tracepoints are set and canceled
    independently. For example, a location or event can have both
    a user-defined and a predefined tracepoint. Canceling the user-
    defined tracepoint does not affect the predefined tracepoint, and
    conversely.

    To cancel only user-defined tracepoints, do not specify
    /PREDEFINED with the CANCEL TRACE command (the default is /USER).
    To cancel only predefined tracepoints, specify /PREDEFINED
    but not /USER. To cancel both user-defined and predefined
    tracepoints, use CANCEL TRACE/ALL/USER/PREDEFINED.

    In general, the effect of CANCEL TRACE is symmetrical with
    that of SET TRACE (even though SET TRACE is used only with
    user-defined tracepoints). Thus, to cancel a tracepoint that
    was established at a specific location, specify that same
    location (address expression) with CANCEL TRACE. To cancel
    tracepoints that were established on a class of instructions
    or events, specify the class of instructions or events with the
    corresponding qualifier (/LINE, /BRANCH, /ACTIVATING, /EVENT=,
    and so on). For more information, see the qualifier descriptions.

    To cause the debugger to temporarily ignore a tracepoint, but
    retain definition of the tracepoint, use the command DEACTIVATE
    TRACE. You can later activate the tracepoint (with ACTIVATE
    TRACE).

    Related commands:

       (ACTIVATE,DEACTIVATE,SET,SHOW) TRACE
       CANCEL ALL
       (SET,SHOW,CANCEL) BREAK
       (SET,SHOW) EVENT_FACILITY