just got it from a
forum
Here's a list of model numbers and where they are from, letters
are not added to numbers for the regions on this list except for
the first models released for the region, example "K" or
"KCW".
Model Number----Country/Region------Region Code---Comments
PSP-1000---------Japan-------------------------2----------Basic
Model
PSP-1000K-------Japan-------------------------2--------- Value
Pack
PSP-1000KCW---Japan-------------------------2----------Value Pack -
White
PSP-1001K-------North America---------------1--------- Value
Pack
PSP-1002K-------Australia/New Zealand-----4 --------- Value
Pack
PSP-1003K-------UK----------------------------2-----------Value
Pack
PSP-1004K------ Europe-----------------------2-----------Value
Pack
PSP-1005K------ Korea-------------------------5-----------Value
Pack
PSP-1006K-------Hong Kong/Singapore------3-----------Value
Pack
PSP-1007K-------Taiwan-----------------------3-----------Value
Pack
PSP-1008K-------Russia------------------------5-----------Value
Pack
PSP-1009K-------China------------------------ 6-----------Value
Pack
not sure is it true or not, mine is the 1001 
