This parameter specifies whether or not the value of ⎕PW is derived automatically from the current width of the Session Window. If Auto_PW is 1, the value of ⎕PW changes whenever the Session Window is resized and reflects the number of characters that can be displayed on a single line. If Auto_PW is 0 (the default under Windows) ⎕PW is independent of the Session Window size.

See also Auto PW.