As well as the Countryside Code, there are a number of others which provide useful advice and guidance.
Commonsense advice on keeping safe at the beach - Beach safety advice (RNLI).
To help the three million adults and countless children to carry on enjoying this most rewarding and peaceful of pastimes – Birdwatchers Code (RSPB)
For a motorist, motorcyclist, cyclist, pedestrian or horse rider - Highway Code (GOV.UK).
Moorland Visitor's Code
Developed by the Moorland Access Advisory Group, it is based on the Countryside Code but with additional information for accessing moorland - Moorland Visitor's Code (Moorland Association)
Scottish Outdoor Code
The Countryside Code applies to England and Wales, but Scotland has its own Outdoor Access Code (Scottish Natural Heritage)
Advice and information about water safety - Water Safety Advice & Information (RoSPA)
For boating, cycling, angling or using an unpowered craft on inland waterways - Waterways Code (PDF) (British Waterways).