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.