In reply to J1234:
Councils, by law are supposed to update their definitive map every 5 years. Some do it more frequent, some don’t bother. Some digitise it and put it online, some don’t. Sheffield don’t and apparently it is in several sections which you have to make an appointment to view.
Some councils are really quick to put on permissive rights of way (and also sign them on the ground) but generally the public don’t get to know about them until the OS decide to update and even then the OS don’t find them all. Barnsley Council is quite good.