Not having ready access to a GPS device, my method of mapping footpaths and bridleways is fairly traditional. I get out my Ordnance Survey 50k map and go and walk the paths. When I get home, I trace the route that I walked on to the aerial photograph. I have a good memory for landmarks, and I take photographs where I am likely to get confused.

On further reflection, this may lead to some interesting license issues.

Let's say for instance that you are following a footpath and reach a small copse of trees. On one side there is a farmer's track but the OS map shows that your footpath goes around the other side. It is quite likely that this is steganography, an intentional error that the OS has included in their map to catch out people who copy it. However, generations of ramblers before me have reached the copse, consulted their map and followed it religiously. As such, there is a well-trampled path around the awkward side of the copse. In the absence of signposts, how does one know which is the correct route?

This problem is much more common than you may suspect. On one walk alone I came to a copse exactly as described above, and a little further on there was another farmer's track that skirted a field while the OS map told me that the right of way lay straight across the middle. Whether this was true or not, generations of ramblers with the same OS map had taken it to be so and there was a trampled path running parallel to a perfectly good farm track 20 yards away.

We OSMers all try and avoid license issues by getting the information for ourselves, but if we get lost where do we go for confirmation? If you ask the council, chances are they'll pull out an OS map to check. What do we do?