i'm a medical anthropology grad student and took a course last year in which we looked at the practice of biomedicine. i became interested in classification and how it relates to the way that (physical) signs are put together to form a diagnosis. and also how classification relates to medical protocal (if patient is X, that can lead to Y...and then to Z which means that the patient has THIS AILMENT). i mean, i am no expert on this and i am not even specialising on this for my research, but i like seeing how signs can abstracted and put together to make a different sign. i don't know anything about classification of medical subject headings, but am now curious.