| HCOGAS100000 | Introduction |
| HCOGAS200000 | Background |
| HCOGAS300000 | Law |
| HCOGAS400000 | Technical guidance |
| HCOGAS500000 | Control best practice |
| HCOGAS600000 | Procedure tables |
| HCOGAS700000 | Reference |
| HCOGAS800000 | Glossary |
(This text has been withheld because of exemptions in the
Freedom of Information Act 2000)
