WB - Practice of Medicine 38 WE - Musculoskeletal System 37 WW - Ophthalmology 36 WH - Hemic and Lymphatic System 31 WG - Cardiovascular System 28 WM - Psychiatry 26 WS - Pediatrics 26 WA - Public Health 25 WI - Digestive System 25 WK - Endocrine System 25 WQ - Obstetrics 24 WO - Surgery 23 WL - Nervous System 22 WU - Dentistry. Oral Surgery 21 WC - Communicable Diseases 16 WP - Gynecology 13 WV - Otolaryngology 11 WN - Radiology. Diagnostic Imaging 10 W - General Medicine. Health Professions 9 WJ - Urogenital System 9 WR - Dermatology 9 WX - Hospitals and Other Health Facilities 9 WF - Respiratory System 7 WD - Disorders of Systemic, Metabolic or Environmental Origin, etc. 2 WT - Geriatrics 1 WY - Nursing 1