A National Public Health Language for the UK PHITS has been integrated with the UK Health Development Authority's Public Health Information Thesaurus 77 and two other controlled vocabularies, to create the National Public Health Language (NPHL) for the UK (Figure 11) . The development of a common public health language is intended to facilitate interoperability and improve the efficiency of searching for and retrieving, public health information and resources held on websites and in databases. All organisations that were already using PHITS have agreed to move to the NPHL when version one was available (December 2004 78 ). NPHL users will have both a public health biased classification system; and a powerful, thesaurus-driven, categorisation and searching mechanism for use on web sites. 79 Figure 11 shows the entry website for online access to the NPHL (left side) and top-level classes and their definitions (right side).