pro rec'd means professional recommended.
It's the first step in gettting accepted to OCS. When you submit your package to the CNRC (recruiting command) they will review your app based on all the stuff you submitted (GPA, test score, LOR (letters of recommendation), personal statement, etc) those are your ADVDOCS (advance docs)
If they like what they see, you'll get a pro rec. Then you have to get a physical, and might need to do a PRT (physical readiness test) Once you finish that, you'll resubmit the package, called FINDOCS now. If they still like you, you'll get a final selection
I've heard of some people getting a pro rec, but not getting a final selection. Hope this helps