You can use it to monitor power supply failures or limit yourself in overclocking LED with “+” and GPIO23 indicate the operating mode:

• Green - 5-volt present: PoE or USB-C or 5v direct
• GPIO23 Low

• Orange (Green and Red together) - 802.3at Type 2 operating mode, PoE+
• GPIO23 High
• Blade can take up to 30W power (22W for RC2)