In journals, unexplained abbreviations cause frustration and confusion,1,2 and the same is likely to be true of case notes from an unfamiliar specialty. Serious drug errors have arisen from misunderstanding of abbreviations.3,4 With the changes in medical working hours in the UK, it is now commonplace for a doctor to cover several different subspecialties. We therefore designed a questionnaire to assess how well some abbreviations widely used in ear, nose and throat surgery (ENT) were understood by junior doctors in other specialties. The thirteen chosen abbreviations, selected from those previously judged 'acceptable' in operation notes,5 were as follows: TAG SMR=submucous resection; SMD=submucous diathermy; DIT=diathermy of inferior turbinate; FESS=functional endoscopic sinus surgery; MUA=manipulation under anaesthesia; PNS=postnasal space; EUA=examination under anaesthesia; OE=otitis externa; CSOM=chronic suppurative otitis media; OME=otitis media with effusion; TM=tympanic membrane; FB=foreign body. For each of the abbreviations, the questionnaire gave a hint of the context—for example, 'name of operation' or 'diagnosis'. Participants were also asked for reactions (from 1=strongly disagree to 5=strongly agree) to the statement that 'any doctor should be able to read and understand notes from any specialty'. The questionnaire was distributed to all junior doctors attending lunchtime meetings at two different hospitals (no duplication)—namely, 4 specialist registrars, 20 senior house officers and 21 preregistration house officers, in specialties including accident and emergency, orthopaedics, general medicine and general surgery; none had held a post in ENT. Answers about abbreviations were scored as either correct or incorrect, though with some latitude if close enough for the clinical sense to be preserved. The response rate was 100%, and Figure 1 shows the rates of correct answers. There was a tendency to agree with the proposal that doctors should be able to understand notes from any specialty (median score 4). Figure 1 Results of survey This small study indicates that 6 of 13 commonly used abbreviations in ENT were unclear to more than 90% of junior doctors from other specialties. With the European Working Time Directive, cross-cover will be an increasing feature of life in the National Health Service; and, if abbreviations continue to be used in the traditional manner, medical notes may be incompletely understood by the doctor on call. The solution is either to ban abbreviations from medical notes or to distribute widely a list of those acceptable, with explanations.