You can mark details in the drawing with detail marks.
In an open drawing, on the Drawing tab, hold down Shift and click Detail mark.
In the Detail Properties dialog box, enter the name for the detail, and modify the detail boundary and detail markuser-created symbol that includes a set of mark elements, identifies the point of creation of the detail view, and is displayed in the source view
properties, as desired.
The shape of the detail boundary you select affects the way you select the area for your detail.
Click OK or Apply.
Depending on the selected detail boundary shape, do one of the following:
If the shape is Circle , pick the center point of the circle and then pick a point on the circle.
If the shape is Rectangle , pick corner points for the rectangle.