The NILOBJ system call creates an access to the special null object and places it on top of stack.
The null object does not accept any requests and is only useful as a placeholder, to fill in slots for missing arguments (see REQ, SUCC, SELECT and CHECK). The null object has the null type (see also NEWTYPE).
The access created by NILOBJ does not belong to any group, and is marked as temporary.
In case of successful execution NILOBJ does not change the result code.
If stack is already full NILOBJ returns error code ERR_STACK_OVERFLOW.