[CQ-Contest] 160M DX Window question

[Doug Smith]

[warning - dumb question alert]

I see various references to the DX Window on 160 Meters.  In some places it's 
listed as 1830 to 1835 and in others as 1830 to 1840 and maybe to 1850.

My questions are:

What frequencies are generally considered the DX Window?

What is the general practice regarding the DX Window?  Do we operate split 
when working DX to stay out of the window or do we work them on frequency *in* 
the DX Window?

Any enlightenment will be appreciated -- especially as pertains to the 160M 
contests.

See you in The Stew!

73,
-Doug, W7KF