PM&S-36 is the old residency model that signified a 3-year program. That's been replaced by the PMSR model since all residencies are 3 years. RRA means that the program has an added credential in reconstructive rearfoot and ankle surgery. If you graduate from a program now that doesn't offer the RRA credential, that does mean that you can't obtain board certification in reconstructive rearfoot and ankle surgery. Some programs haven't switched over to the new model I think so you may see some PM&S-36 programs, but they are essentially the same as PMSR/RRA.