Clarification about line out

I’m picking up a MKII this week and have a quick clarification question about the line out. The specifications say that it can be used for either a stereo headphone or balanced out. Is the balanced out a TRS to a standard line level balanced feed (at +4 dBu?) or TRS to an un-balanced pair? Just not sure how this is working as both simultaneously. I have TRS to XLR for line into my mix or just TRS to TRS for that or a DI but just checking to see if I need to get some kind of insert cable or something to get the proper signal out?