There is a subtle little trick to Annotating punch tools in flat sheet metal parts that I came across the other day, and I thinks it’s worth sharing, as it is one of those little things that can catch you out from time to time.
If you have created a sheet metal component that is already flat (like in the picture below), and you want to use the standard sheet metal punch Annotation tools, you may come a little unstuck. The trick is that you need to first create a flat pattern within the part (so that it is available on the drawing).
When creating the 2D drawings, ensure that you select Flat pattern when you place your drawing view.
You will now be able to add Punch Note annotations to your drawings.