Why two manufacturer numbers for the same lens (EF 50mm f/1.4)???

Hello

I am going to buy a Canon EF 50mm f/1.4 but notice when searching on
the web that there appears to be two versions of this lens: one has the
manufacturer number 2515A003 (in most countries) and one 2515A004 (in
e.g. Germany). Can anyone tell me what the difference is?

I am aware of the "grey market" vs. "USA" lenses when you buy from US
dealers, however a quick check at for instance B&H Photo reveals that
these two types have the same number (2515A003).

Thanks for your help