I believe it is just the sticker they slap on your ECU once it's loaded with all the module data, but that's a SWAG from my part. This has been mentioned to be a milestone towards the end of your production in the many "tracking" posts. You'll see if this has happened at the top of the Motorcraft website where you found your modules.My in production date now shows as 1/7. Modules are turning on, but I don't really know what that means.
@jybell what is a tear tag?