NPPF Open Space definition - Public forum - Planning Advisory Service (PAS)

Can anyone help with interpreting the NPPF definition of "open space?" I would be interested to know if anyone else has looked into this or has had a recent appeal decision. The definition for Open Space in the NPPF Glossary is: "Open space: All open space of public value, including not just land, but also areas of water (such as rivers, canals, lakes and reservoirs) which offer important opportunities for sport and recreation and can act as a visual amenity".