Is there a difference in EXI and EXP codes?

[Zippadeedoo Dave]

I noticed that Mousesavers AP code was EXI and I used it with no problems for dates on Labor Day weekend, but at that time i never got an advance e-mail from Disney about it nor did I see anything on the passholder website about it. Usually i get the advance notice e-mail from Disney a day before AP codes come out. But now i see on the passholder site that they have a code for the same dates and prices as the EXI code but the code is EXP.

So is there any difference in the codes or did mousesavers get thier own AP code this time? Is Disney testing to see how many are getting information from the internet?

Just thought it was kind of strange.