This paper discusses theoretical and clinical aspects of transcription practices in clinical linguistics and phonetics, and speech-language pathology. We consider the purpose of transcribing and transcripts, and distinguish between the transcript as a product and transcribing as a complex, cyclical process that forms an integral part of data analysis. Operational relationships between transcriber, data and data source, and the reader are addressed. We suggest a multi-layered toolkit approach to transcribing, based on six guiding principles.