Quote Originally Posted by catymag View Post
My experience:
I can see CXs and use EPM with FID 800 made with my unit id even if I put them in sd-
I never used sd id-
Can someone test it?

Yes it will work with booth UnitID and/or CID as the parameter for creating the unlock code. The problem would be that the memory card can't be "portable" and fully functional in another unit if unlock codes are based on UnitIDs. Otherwise no problems at all with the specific unit and UnitID that was used to create the unlock code.
One advantage of using the CID is that it's not connected to Garmin and stored with your myGarmin account. The risk of publicizing any of your CIDs would be minimal compared to posting your UnitID in plain text.