If you want a thorough explanation of “permissive paths” then read the comment on the previous post that explains what they are and why the Church of St Denys has erected this sign.  The Church is 15th Century and the stained glass windows were just recently repaired and made safe.  An expensive but vital project.  Sadly, as one part of the building is restored another needs repair and therefore, at any time and for the sake of safety, the path through the churchyard may have to be closed.  Our green and pleasant land is full of similarly old and beautiful buildings that need constant maintenance at prohibitive cost.