"The Health Development Agency and England's Public Health Observatories (PHO's) have developed a unified Public Health Language (PHL) [formally known as the National Public Health Language] to facilitate interoperability. The first version of this language was officially launched at a conference on the 20th December 2004. The PHL is the result of integrating the former HDA's 'Public Health Information Thesaurus' with the PHOs 'Public Health Information Tagging System' (PHITS), which are no longer active as they have been superseded by the PHL. The Public Health Language has been adopted by many organisations and can now be considered as 'the' Public Health Language for the UK and Ireland. Now at Version 2.0 (and the PHL sub-set of SNOMED CT)."