JCAHO requires that your bulletin board hold limited information and that all sheets of paper on the board MUST HAVE TACKS IN ALL FOUR CORNERS.
Apparently if your don't have it tacked down in four corners you could lose your accreditation.
I can understand their concern about the whole four corners thing. Paper can be dangerous for the following reasons:
1) Someone could get a nasty paper cut from that fluttering piece of paper.
2) Lets say the paper comes loose due to only having one tack, it could become a missile and take somebody's eye out.
3) A wind could come by and move the paper around helter-skelter and your eyes could follow that motion, causing dizzinessand a fall to the ground perhaps requiring boarding and collaring.
4) The paper could become loose, fall to the floor. You bend over to pick it up and herniate a disk. You become addicted to narcotics and lose your job as a nurse becoming an aimless drug seeker.
5) The paper becomes loose, a random gust of wind takes it down the hall. You chase after it, slip on the floor, hit your head on the corner of a desk. You develop a massive head bleed and become a vegetable.