There have been some complaints that the term ‘diagnostic formulation’ has caused difficulties to examiners and candidates for the MRCPsych Examination, and APIT have recently written an open letter to the chief examiner about this (Bulletin, April, p. 67). This has caused me to think about the problem, and to jot down a few thoughts (most of which I may say I have stolen from other people). Initially examination candidates were expected to submit a formulation in writing, but this is no longer the case. Examiners, however, still expect a brief diagnostic formulation. I have therefore summarized four accounts of ‘formulation’.