decode an internal sticker (not a serious topic)

[vaklaff]

In the other thread I mentioned a 65 I recently bought and cleaned. While disassembling it, a small piece of paper fell out. It's size is about 4x1 cm, the back side has traces of some glue that dried long ago and the front has this hand-written text:

Code:

11-16-83 DB  
            BN
XT,CA,CD,KX,CX

My guess is that some Mr. or Ms. D.B. gave the calculator a check or service in 1983. Obviously the person is American - the nonsensical date format gave them away :-) But I have no clue what the rest of the text means. Any ideas, my dear Watsons?