Projects The numbering system changes here - an extra level has been created with the use of letters. Not all files in this series include letters however The following letters are used, and are as follows; A - Pilot Areas B - Associate Trial Areas C - Conferences D - Consultative Committee / Advisory Group E - Evaluation F - Examinations / Syllabuses H - Materials J - Staffing / Policy K - Monitoring Group M - Dissemination and After-Care N - Literature P - Accommodation, Finance and Equipment U - Steering Committee