Among the many headaches of medical practice, the result of misunderstanding, misuse, or mis-taking of prescribed medicaments is not the least. Part of the artistry of medical management lies in the accuracy, detail, and ingenuity of prescribing and instructing in the use of what is prescribed. This is an area in which the strangest errors, humorous and serious, occur. "As directed" on a label, which had been verbalized as "soak for 15 minutes every 4 hours," may be remembered by the patient as "soak for 4 hours every 15 minutes," or what was ordered to be applied on the skin is swallowed instead, and so on for scatterbrained behavior that produces telephone calls, if nothing more alarming. With some patients no amount of instruction, even the most meticulous review of orders, sets things right; some people have a genius for doing the wrong or illogical thing. Nevertheless, writing out precise