Medical prescription
A prescription, often abbreviated ℞ or Rx, is a formal communication from a physician or other registered health-care professional to a pharmacist, authorizing them to dispense a specific prescription drug for a specific patient. Historically, it was a physician's instruction to an apothecary listing the materials to be compounded into a treatment—the symbol ℞ comes from the first word of a medieval prescription, Latin: Recipere, that gave the list of the materials to be compounded.
Read article on Wikipedia