Ok.. here's the scoop...
I called mazdausa and asked about the sticker. He couldn't give me much info except that the date on the sticker happened to coincide with the date my car's subwoofer was replaced or installed at the port.
So, it seems like they're doing some inspections at the port and when something needs correcting, they do that work and place a sticker inside the engine bay. I'm speculating that the 747 code I have refers only to Subwoofer replacement but Mazda customer service couldn't verify that this was the case.
Seems the date is the key for the info they have when you give them your VIN. This explains why there are some different codes out there dealing with other fixes done at inspection time. So, it's good to know that they checked them out. I also got my production number during the same call. Cool... I'm 932.