Sorry, but I do not have my code book with me at the present time.

<Removed Incorrect Statement> Don

There is a physical limit imposed by the cord length, because there are only two lengths available, that I know of. 4' or 6'.

As soon as I get a moment, I'll verify this in my 2008 code book.

Okay, I found the code section that I believe applies. It is not the length of the cord that is regulated, it is the position of the outlet that is regulated.

It is in chapter 2, Article 210.50 (C):

Appliance receptacle outlets installed in a dwelling unit for specific appliances, such as laundry equipment, shall be installed within 1.8m (6 ft.) of the intended location of the appliance.