Rigour is needed in the construction of health terminologies to avoid introducing ambiguity and error into clinical records. When two large scale terminologies (SNOMED RT and Clinical terms Version 3) were merged to form SNOMED CT^® a number duplicate and ambiguous concepts were introduced. The SNOMED nursing working group was tasked with producing a draft editorial policy to resolve duplications and ambiguities in terms related to education, advice and counselling. Consultation and input from two opportunistic workshops resulted in a draft policy that was tested before being approved for use. Education and counselling were identified as different concepts but the consensus view was it was not possible to differentiate between related concepts such as advice about, teaching and training in a way that will allow unambiguous use in practice. Expansion of existing working groups and improved communications infrastructure will support more widespread clinical input to SNOMED CT^® maintenance and updating.