Below is an explanation of the walking grades:
Minimal walking required, usually 1 mile or less at a time. Almost always on level trails and paths. Often roadside. Assistance usually easily available.
Winter: There may be some snow and ice, but this will usually be limited or avoidable.
Walks usually up to about 5 miles. Often involve some good paths, but also steep/loose/wet/muddy sections which may not be avoidable. Assistance will usually be available. Obstacles such as stiles, gates and boulders may be encountered.
Winter: Snow and ice covered sections may be unavoidable but any slips should not have serious consequences.
Walks will involve long sections without good paths, with long periods of ascent and descent, sometimes over rough and/or slippery terrain. Distances will usually be over 5 miles. Obstacles such as boulders, stiles, deep heather, stepping stones, etc will occur. Assistance will be available, but guests should have good mobility and fitness.
Winter: Snow and ice cover, together with the steepness of the terrain, will mean use of ice axe, crampons and perhaps helmet is essential.