I am an RN who has worked in some rather interesting places:  county jails, state prisons, juvenile facilities, places with lots of insect/vermin activity, etc.  In lieu of carrying a purse I have worn one of these for the last 20 years to carry my I.D. and a couple of dollars to get me back and forth to work.  No one suspects I wear it under my uniform.  One of my fellow nurses carries her I.D. and a few bucks in her shoe.  This is ever so much more comfortable.