This utility lets you launch commands by dragging mouse patterns in the viewport. When you click the Strokes utility button, and modeless dialog appears containing a single “Draw Strokes” button. The Strokes system is also available as a middle-mouse button option that doesn’t require the utility or the modeless dialog.
Draw Strokes: Click this, and then drag in the viewport to draw a stroke
A dialog box appears asking you to define the pattern or continue.
The define stroke dialog box appears.
The pattern is now defined for the chosen command.