PTO stands for Please Turn Over. It is usually written at the bottom of a page to request the reader to turn the page. It is used to show that additional information is given on the other side or next page. For example; you are writing a paper of science. On one page after writing the description you want to draw a diagram but you are left with only five lines below the description where you can?t draw the complete diagram. So you can write the PTO below the description and draw you diagram on the next page. It tells the reader, it does not end with description on this page there is some more information on the next page.