As a brand new owner of a not-so-new '01 X5, I've been looking it over, and trying to match items on the truck to corresponding info in the online owner's and workshop manuals that I've downloaded. I saw this circular sticker attached to the driver's side door frame, but can't find any reference to it in either source. What # is ticked-off (321 or 341?), and what does it mean?

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