Please tell me where to find how to create "auto-serifs" in the handbook. Thanks

Please tell me where to find how to create “auto-serifs”

Perhaps you are thinking of this:
8.3.1 Corner Components, page 109.

Thanks, George. That’s exactly what I was looking for. I had forgotten the technical terms for this procedure. CM

Also, take a look at the Reusing Shapes: Corner Components tutorial.