Yamaha letter code repeated letters ?

[Muppet]

Hi all,
All the sites I google state that the code letters are repeated and to use your better judgement if it's a 2011 or a 1990 model.
My question is for a motor I plan to travel to and buy so I can't check much else to guarantee it's a 2011.
Even googling images of outboards of these ages doesnt clearly show a style or color difference to my untrained eye.
What is the secret?

I can't remember how to post pictures but this is the codes.

YAMAHA 40VMHD
6H4K L 1019143
yamaha motor Co., Ltd. D
MADE IN JAPAN
Pays d'origine japon



Any help or explanation of why it's the newer model would be great thanks.

 

[Muppet]

Sorry I thought I put this in yamaha not mercury. Feel free to shift it.

 

[boscoe]

Definitely not a 1990. Definitely made after 2008.

 

[Muppet]

Thanks for that, what is the thing that makes that obvious?
Going Sunday to look at the 40hp yamaha.