DCLG has recently published Planning Practice Guidance to support permission in principle and brownfield registers of land suitable for housing. A national data standard that all local planning authorities in England are encouraged to follow in preparing and publishing their brownfield land registers has also been published.
The weblinks are as follows:
https://www.gov.uk/guidance/brownfield-land-registers
https://www.gov.uk/guidance/permission-in-principle
https://www.gov.uk/government/publications/brownfield-land-registers-data-standard
Any queries should be directed to: brownfieldregistersandpermissioninprinciple@communities.gsi.gov.uk.