We’re all familiar with the 4-5 sticker codes when buying produce. “PLU codes are 4 or 5 digit numbers and will appear on a small sticker applied to the individual piece of fresh produce. The PLU number identifies produce items based upon various attributes which can include the commodity, variety, growing methodology (e.g. organic), and the size.” 
These codes also tell whether the product being purchased is conventionally or organically grown.
There are many sources reporting that PLU’s have no significance and that the numbers are randomly assigned and ONLY for identification purposes. However, the International Federation for Produce Standards, the department that issue PLU’s, have a completely different story. Each number in the code does not have individual significance, however the prefix and length of the number does have significance as it relates to the methods in which the produce where grown.
“The 4-digit PLU codes for produce are randomly assigned within a series of numbers within the 3000 and 4000 series. There is no intelligence built into the 4-digit code. For example, no one number within the 4-digit number represents anything in particular. The 4-digit codes are for conventionally grown produce. 5-digit codes are used to identify organic produce. The prefix of '9' would be placed in front of the 4-digit conventionally grown code for organic produce.” 
Here’s a visual representation of what the above report and what it really means for your health:
Become and informed consumer. Perform your produce PLU search here.