It is now possible to push room and rate codes instead of the ids within the OTA_HotelInvCountNotifRQ, OTA_HotelRatePlanRQ, and the OTA_HotelBookingRuleNotifRQ.
This is mandatory for SmartCONNECT for CRS interfaces. Those codes can be only uppercase characters, numbers and hyphens.
Details can be found on the PMS rates & availability introduction page.