You can use the “@” symbol in any case that requires a coordinate input. If you want to draw concentric circles draw the first circle. Draw the second but use the “@” symbol for the center point. It will select the center of the first circle drawn.
In my post, “How to Break a Line Like a Pro” I showed you how to use the “F” or first option in the break command to break an object at a specific point. In Tip Number 2, I have you select the exact same point to break an object in one place. Alexandre Serdakowski, a reader of this site and a Head Draftsman, reminded me of the last point feature of the “@” symbol and that the break command would be a great use case. Start the break command, select the object, type F, pick your point, then for the second point type in @. It’s much easier than selecting the same point again.
Also keep in mind that if there is no last point in a drawing yet then using the @ symbol will draw your object point at the origin (0,0).