Hello "The Vyne", and welcome to OpenStreetMap!
I wonder if there's been a bit of a miscommunication about "permissive access" here?  Something that the general public have a legal right to access (e.g. a public footpath) would be "yes" or similar.  "permissive" means that people are allowed to access it, but the land manager might remove that access at any time.  "customers" means paying customers only, and "private" means only the people who own the land or people they explicitly allow (such as someone delivering the post).
If you've got any other questions, you could pop in to the UK forum https://community.openstreetmap.org/c/communities/uk/86 (login with your OSM login) and ask there.  I'm pretty sure that there are people there with long memories that stretch back to the join OSM / NT training that happened at Clumber many years ago!
Best Regards,
Andy