Fox, an order card is an original card with all the information of the order for that particular gun. They are maintained by the Fox Collectors Club, you are allowed 1 free look up a year with membership. They are missing some cards from the early guns and I am not sure about the Savage guns.
Some of the cards will have some interesting details,dimensions, etc for very special orders. Others such as the one for my XE just have bare info as it was ordered for stock for the EK Tryon Company.