You can list all tax keys, you entered. 

With a double-click at one tax key, you can change it as 
described in the description in chapter 6.3.7.

You can click on a tax key and delete it with the point 
"Delete" in the menu "Edit", or with the Del-Key.

If you want to print the list, you must choose the point 
"Print" in the menu "File".