Do not write the PIN on your card or on a piece of paper. The PIN will allow a thief to gain unlimited access to bank machines around the world. When using your card, watch to be sure that extra imprints of your card are not being made. Making another imprint of the card and filling in the information later is a common occurrence. When a merchant returns your card to you, make sure that it is your card.
Mistakes can happen, and cards get switched.
The person who gets your card may not be as honest as you. Avoid signing blank charge receipts. Always insist that the exact amount be entered on the receipt before you sign. Always sign your receipts with an ink pen. If your credit card is stolen on campus, report it immediately to the Ohio University Police Deportment, 593-1911, located at 135 Scott Quad.