It might be one of those things that you request to be on the label? I'm not certain though I know with SGC, you can add the word "ROOKIE CARD" or something to that effect on the invoice and they will add that to the flip. I would imagine it's the same with PSA and BGS but can't say for sure.
Looking over the few cards I have graded, BGS doesn't seem to do it whatsoever. SGC denoted it on my cards without prompting, but they also tag cards that are not "true RCs", as in when listed here on the Beckett site, they do not have the "RC" attribute.