I received my shipment of 432 A123's last week and I have the same sticker. Kerry is right on, it seems to be what the Chinese are doing to have lower duties/fees. The top two cells in all my boxes were labeled this way.
PL6 is short for PowerLab6. It's a charger this is used by R/C hobbyists that will do multiple battery chemistries, and it has lots of useful features for our purposes (capacity testing, internal resistance, etc.). You can buy them from Revolectrix at: http://www.revolectrix.com/
I have 4 of them and am just beginning testing of all my cells. There are many others here on the forum that are/have used these units, and even a thread about a standardized testing procedure for A123s using them (although personally I don't want to discharge as low as they are going).