1 /RAD
/RAD=n /NORAD Specifies an additional memory section if you want to specify more than one RAD for a single reservation. Use /NORAD to add a memory section without specifying a RAD.
2 /SIZE
/SIZE=size of reserved memory, in MBs Specifies the number of megabytes to be deducted from the system's fluid page count for this memory-resident global section when the VMS$RESERVED_MEMORY.DATA data file is read during system initialization.