What happens when you set VPROTATEASSOC System Variable to 0?

VPROTATEASSOC system variable allows you to control rotation of the viewport and its drawings inside. When it is set to 1 When you rotate viewport drawing within also rotates but when it is set to 0 rotating viewport doesnot make anychamge in the oriantation of drawings.

Whwn we set VPROTATEASSOC System variable to 0, then the viewport is rotated but the inside view does not change.

When the registry value sets to zero, the inner view does not rotate along with the viewport rotation.

When a viewport is rotated, the view inside is not rotated.

Agreed with Vikash's answer.

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.