What it is the smallest size barcode that can be read with SparkFun 2D Barcode Scanner Breakout #SEN

I have ordered a SparkFun 2D Barcode Scanner Breakout #SEN-18088 & look forward to playing with it. I’m especially curious to know what it is the smallest size barcode it can read? Any suggestions welcome - thanks!

A smallest size isn’t specified in the data sheet, you will need to determine this experimentally.