Frequent tipster Danny Korem explains an AutoCAD system variable that controls what happens to a viewport's contents when the viewport is rotated.
"Sometimes, while organizing sheets, you need to rotate viewports within drawings. If the viewport keeps its actual orientation when rotated, check the VPRotateAssoc variable. When it's on (1), rotating the viewport will rotate the viewport's content along with its frame. When VPRotateAssoc is off (0), it won't. Some other applications, such as drafting a façade out of a plan drawing, can be easily achieved this way. Then you can use the viewport to locate the elevation within the viewport while hiding the plan view. All of that with no need to master the user coordinate system."
Notes from Cadalyst Tip Patrol: AutoCAD is a fantastic tool. One of the reasons it became widely used is because it provides many ways to get the job done.
Case in point: rotating views. The addition of paper space in AutoCAD v11 provided a platform to create drawing sheets, and made things so much easier. There are many ways to create a rotated view in AutoCAD. Users can create a user coordinate system where the actual coordinate system is rotated; use the command DView and twist a view in a viewport; create a saved view that is rotated; or use the system variable in this tip and simply rotate the viewport. There are pros and cons to each method, of course, but as long as the VPRotateAssoc setting is turned on, rotating a viewport may be the easiest solution — or at least the quickest.