Where can I find the part number and production code on a boat cover?

The part number and production code (sometimes called tag code) are located on the white product tag that is sewn onto an interior seam at the bow or stern.  If your boat cover came with a storage bag, there will also be a tag located inside the bag. 

Both tags contain the same information. You only need to locate one. See the images below showing where the product tags are located.