Avoiding GM fruit

I came across this tip today for avoiding GM fruits (not sure if it works with vegetables). It did say that this is not foolproof, since the PLU labeling is not mandatory, but I thought it might help a bit and so am passing it along.

According this this article, GM fruit PLU codes have five numbers that begin with the number 8; whereas organically grown fruit PLU codes have five numbers beginning with 9. Non-GM, conventionally-grown fruit PLUs have four numbers.

Hope this is of some help!
Dee