https://www.faa.gov/documentLibrary/...lar/90-108.pdf
This will lead to the FAA guidance on the subject.... basically within certain limitations RNAV systems can be used in lieu of VORs that are out of service, which also implies that raw data monitoring is not required. This is normally cooked into individual operators’ operation specifications and FOM. Typically navaid raw data monitoring is not required except on the final approach segments of instrument approaches based on said navaids, assuming the RNAV equipment meets the requirements and is working properly.
If one is flying a procedure using ONLY the raw data and NOT using RNAV, the following guidance exists in FAA land which recommends the only way to positively identify a VOR is by listening to the morse code or by reading the auto-decoded identifier on your fancy glass cockpit:
https://www.faa.gov/air_traffic/publ...section_1.html
This one is from the AIM, which is technically non-regulatory. However in many past enforcement cases, a pilot’s failure to follow the guidance therein has been deemed “careless and reckless operation” and cost them their certificate. So it might as well be regulatory.
Again this is USA FAA guidance only..... but it is guidance we are REQUIRED to follow on international flights to most everywhere I’ve flown to, so.... there you go. Take it for what it is worth.