DUNOVCLS specifies a SYSOUT class that overrides the class assigned when the SYSOUT data set was allocated. This key is ignored if the resource is not a SYSOUT data set. When you code DUNOVCLS, # and LEN must be one, and PARM contains the overriding class.
The SYSOUT class characteristics are used in processing the output, with the exception of the spool space allocation attribute. The spool space allocation for the SYSOUT is unchanged from what was specified at data set allocation time, either through the SYSOUT class definition in JES or through dynamic allocation.
KEY # LEN PARM
0018 0001 0001 C3