This assumes track number is the same as “platform number”. Besides having to know whether there is a track number, this fails to consider different stops on the same track corresponding to different platform sections. Tag:railway=platform_edge - OpenStreetMap Wiki
If it is recommended that local_ref= only be used on those cases, the data becomes difficult to check. A transit application using =stop and =platform only won’t have the railway:track_ref= on the railway= track. They would need to know this, and do extra processing to join the railway:track_ref= from the railway= track to the =stop .
=stop local_ref= != railway= railway:track_ref= :
- UK: 83 instances. It’s common to use
railway:track_ref=for the track outside the station. At through stations, this entangles. Even if something else is used for up/down and fast/slow, these seem to be a validrailway:track_ref=- Milton Keynes Central:
=Reversible *fast and slow track between fast and slow tracks paired by use. Way: West Coast Main Line (278034652) | OpenStreetMap - Faversham, and Ramsgate Stn: up and down
=* Passenger LoopWay: Chatham Main Line (217385910) | OpenStreetMap - London Bridge Stn: Up and dn
=*CS, and=DN CX, for Cannon Street, or Charing Cross Stn Way: South Eastern Main Line (35400802) | OpenStreetMap
- Milton Keynes Central:
- Germany: ~410 instances, seems mostly 3-digit
railway:track_ref=- Frankfurt Hbf
- A
local_ref=1aWay: 154494960 | OpenStreetMap - I don’t know what slashing 2 numbers means when there is only 1
=stopWay: Main-Weser-Bahn (154495027) | OpenStreetMap
- A
- Dusseldorf Hbf Way: 636968130 | OpenStreetMap
- Frankfurt Hbf
- France: ~1050 instances
- Switzerland: 220 instances
Maybe somehow related @gymate recently Adding the track side to route=railway relation members