FAA Inspector ID's.
The losses over a 5 year period are wrong. There are probably some missing, but in the last few years the 110A was changed from a horizontal card, with picture, to a vertical card with picture. The new cards have not been around for 5 years.
The newer vertical 110A has the inspectors picture and a halogram over it to prevent changing the picture. So the forgery or stolen card needs serious changes to the inspectors looks?? As 411A says, not likely to happen.
If they are doing and en-route inspection in the cockpit they will identify themselves to the check-in staff and present a form of boarding pass from a book that they carry. They then bring that same boarding pass form to the airplane, identify themselves to the cabin crew and request to go to the cockpit. Normally the cabin crew will then take the boarding pass and the inspectors ID to the cockpit to clear it with the captain. The boarding pass form is kept by the captain.
If they are doing an en-route inspection of the cabin they will do the same procedure.
If only doing a ramp check they will present the 110A for entry to the airplane, and carry out the inspection and leave. They will not be on an airplane without a crew on board, nor will they open any cabin door to gain entry.
If they are in the back travelling on business using a ticket they will not necessarily identify themselves and will only surface if they see an issue that needs discussion with the crew. Normally after landing unless it is a serious issue.
That should clear the air??? Any questions??
Speedbird48