Hello MACEDONICUS, I have noticed that you have upgraded some residential and unclassified highways to tertiary along with adding ref tags that begin with ‘O’. For example on this highway (https://www.openstreetmap.org/way/399488924) the tag 'ref=O2045’ was added. I have been unable to find any information regarding these refs and was wondering if you would be willing to share the resource used for these ref additions. I’m also curious if all of the highways with this ref format should be tagged as highway=tertiary. Thanks, and looking forward to hearing from you!