One should always put NAME and CONTACT on the outside of the BAG as well as INSIDe the bag. IN the event your bag has to be checked for some reason it can be identified. Luggage tags have been know to get caught and ripped off via luggage belts. In this case if the airline has to go inside an unloced bag it will do so to try to find out the owners name and contact. I have done it many times when a bag comes to the baggage office with no contact. If you choose to use the airline supplied tags replace them often. I have a plastic tag I got for a buck and I slip my business card inside. I also have this INSIDE my bag. If you are a road warrior and you lose your bag having this info will get your back back to you ASAP.