From Shindong's 'BONAMANA' Thank You notes:
B2B8,B4B9,B3A8,
,B3C6,B4B9,
,A4A7B4,B5B6B2,B5B8,A2B8,
,C3B7B3,B5B6B2,B5B8,B2C7B2,A4B7,B3A8,
,A5B8,B4B8B3,B5A9,A2C6B4,A4A10,
,B3A7B3,B3C6B7B2,B5B9,
The code can be understood with this
A is the 1st row (Q,W,E.R....)
B is the 2nd row (A,S,D,F...)
C is the 3rd row (Z,X,C.V...)
the number next to the letter is the key in that row (from the left to right)
and you end up with something in Korean:
나,리,야
우,리,
결,혼,하,자,
청,혼,하,는,거,야,
사,랑,해,줄,게,
영,원,히,
Which is translated to:
nari,
let's get married,
this is a proposal,
i'll love you,
forever
Again, we do not know what this can mean, if it's a real proposal or a joke. Please wait for any kind of confirmation from Shindong himself.
ETA:
A picture of Shindong & Nari! Credit:『SexyDino☆彡』@
SJ-World.netKorean ELF for deciphering the ~code~ (No link provided on the link. It's SJ-World, though, so it's quite reliable)