Model numbers beginning with ND and MD?

[Marco123]

After reading another thread about their faulty wi-fi signal that commented on the model no. of his ip5 beginning with ND, I realised that mine begins with MD.
Has there been a recent silent hardwrae revision that probably changed the wifi contained in the ip5?
If not then why the sudden change of the prefix in the model numbers?

 

[7even]

No, the only difference in my experience is that retail units are MD and white-box replacements done at the Genius bar are ND.

 

[ROLLTIDE1]

my 2 replacements from Apple were ND

 

[Marco123]

No problem, thanks.

 

[richxps]

So the replacement coming to me in the mail with a MD model is a retail box unit ? Has anyone else with white box replacements have a ND model ?