This sounds like something that's specific to that server, rather than being a general raw
If you want to find out what the raw is you could try this
raw *:*:{ .echo -a $numeric }
Put that into a remote file, then do a whois on the person
You will get back more responses than just the RAW you're looking for, because you'll also get the RAW numerics for the standard whois response
For more help with raws try visiting
RAW numerics