NRf5340DK IO pins voltage level

[AlaBek]

Hello,
I want to know what voltage level are the pins on DK5340 , I am using USB cable for power supply. I read that the DK is compatible with ARDUINO REV3, so does that mean it supports 5v? 
Regards 

[Turbo J]

Nope. None of the I/Os allow more than 3.9V absolute maximum, see PS.

[AlaBek]

So what should I expect when running this DK with Arduino Shield? is there a list of supported shields?
Also what is the default voltage on all pins if I do not modify it?