In reply to redpointillist:
You don't need permission to climb there but there is a code of practice that needs to be followed and you defo need a guidebook to know where you can and can't climb. Also wiping feet, not using toothbrushes are sentential and to reduce the use of chalk or even better, any one bouldering should now use an eco ball. Its a very sensitive area and climbing needs to be done with great care and currently many people do not understand the nature of the rock or environment and go at it like they're in an indoor wall.
The intro of this guide has lots of information and any one climbing on sandstone should read it.
https://rockfax.com/climbing-guides/books/southern-sandstone-climbs/
This is the code of practice as well incase any one had not read it.
http://www.southernsandstoneclimbs.co.uk/p/code-of-practice.html