I believe that the US is for "United States", the other initials are that of the manufacturer, and the numbers represent the contract year ("88" = 1988) which may or may not be the year they were actually manufactured.
WARNING & DISCLAIMER:
SELECT AND USE OUTDOORS AND SURVIVAL EQUIPMENT, SUPPLIES AND TECHNIQUES AT YOUR OWN RISK. Information posted
on this forum is not reviewed for accuracy and may not be reliable, use at your own risk. Please
review the full WARNING & DISCLAIMER about information on this
site.