There are a few marking on the back of the wheel to help you identify the wheel and its specifications.
Max Load Rating - This is the maximum load that a wheel is designed to carry. This load is calculated from calculating 50% of the GAWR (gross axle weight rating). If, for example, the GAWR of your vehicle is 2200lbs, you would need a minimum load rating of 1100lbs per wheel.
Max PSI Rating - This is the maximum PSI that you can inflate the tires to per wheel.
Wheel Size and Offset - The wheel/tire size and offset are typically written as diameter x width and the offset would be the ET. For example, 16x7 ET 0 means it is a 16" diameter wheel x 7" width and an offset of 0mm.
Wheel Model Number - This is typically represented by 2 letters and 3 numbers. In this example, it is XS811
Manufacturing Date - This is the month and year of manufacture. The year is located to the left of the chart. The chart is split up into 12 sections and would have a dot in each section depending on what month it was produced in. In this example, this wheel was manufactured in March of 2016 as it has 3 dots and has the "16" to the left of the chart.