In the opinion of SmartBarf, the difference between raw meaty bones (RMB) and recreational bones is that RMBs are soft enough for the dog to chew up and eat eg poultry carcasses, backs & necks and lamb necks. Recreational bones are larger ones that the dog will chew on but will not eat the whole bone eg beef marrow bones which might be better fed with the knuckle removed to give easier access to the marrow. The knuckle itself will have soft outer cartilage which the dogs will enjoy gnawing on. Dogs can become constipated by too much bone so please supervise and remove before they eat more than their daily allowance.