2013

Snaps to a quadrant point of an arc, circle, ellipse, or elliptical arc.
Intersection
Snaps to the intersection of an arc, circle, ellipse, elliptical arc, line, multiline,
polyline, ray, region, spline, or xline. Extended Intersection is not available
as a running object snap.
Intersection and Extended Intersection do not work with edges or corners of
3D solids.
NOTE You might get varying results if you have both the Intersection and Apparent
Intersection running object snaps turned on at the same time.
Extension
Causes a temporary extension line or arc to be displayed when you pass the
cursor over the endpoint of objects, so you can specify points on the extension.
NOTE When working in perspective view, you cannot track along the extension
line of an arc or elliptical arc.
Insertion
Snaps to the insertion point of an attribute, a block, a shape, or text.
Perpendicular
Snaps to a point perpendicular to an arc, circle, ellipse, elliptical arc, line,
multiline, polyline, ray, region, solid, spline, or xline.
Deferred Perpendicular snap mode is automatically turned on when the object
you are drawing requires that you complete more than one perpendicular
snap. You can use a line, arc, circle, polyline, ray, xline, multiline, or 3D solid
edge as an object from which to draw a perpendicular line. You can use
Deferred Perpendicular to draw perpendicular lines between such objects.
When the aperture box passes over a Deferred Perpendicular snap point, an
AutoSnap tooltip and marker are displayed.
D Commands | 377