THE Regional Council is to revise guidelines for developing public library services in the council area up to year 2001/02 to cope with the forecast of population distribution and the planned development of new towns. The new guidelines, together with the proposed library expansion programme, were recently approved by the Regional Council's Recreation and Culture Select Committee. Alex Ng, chief librarian of the Regional Services Department, said the existing ratios of books and audio-visual materials, Chinese and English items as well as adult and junior books would remain unchanged. The ratios will be closely monitored and adjusted in the light of changes in the useage pattern. The present share of audio-visual materials as five per cent of the total book-stock is proposed to be unchanged as experience has shown that this is sufficient to meet existing demand. Such materials are provided in the form of compact discs, audio-cassettes, video cassettes/discs, slides, films, CD-ROM, and computer software. Two other ratios - three Chinese items to one English item and three adult books to one junior book - will remain unchanged. With the increased utilisation of the council's library services, it is proposed that the planning standard for district libraries be adjusted from one library for every 200,000 population to one for every 150,000. On size of district libraries, the proposed new standard size will be increased from 1,650 to 1,800 square metres to 2,200 square metres. The additional space will be for provision of a purpose-built microcomputer room, a larger newspapers and periodicals Section and more library materials. To sustain the improved services brought by the computerisation of the council's libraries, it has been proposed that the computer system in the libraries should be enhanced from time to time to take account of technological developments and new information needs. Another move is to set up a central reserve stock when space becomes available in the Sha Tin Central Library to provide inter-library loan support to all libraries. This will provide a back-up for popular items which may have a long, reservation list, or library materials which may have worn out. The estimated total expenditure required for the proposed development of library services would be $471 million. At present, the council operates 22 public libraries and three mobile libraries serving all nine districts. Each district is provided with at least one stationary library.