Re-torque drive shaft nut (AWD)

What is your question?

In my maintenance manual it's requesting that I "Re-torque drive shaft nut (AWD)" every 10,000 miles or so. With no other info. I'm mechanically inclined but I'm not sure what nut they're referring to. The 22mm nut on each axle (drive shaft, so 4 of them)? Is there just one nut that needs to be torqued that's specific to the new AWD-E Prius models? I'm kinda at a loss here and just wanted to get some info before I drop money on a torque wrench and the correct size socket.