Of course, if we offer the user the opportunity to customize the display of individual entities, it makes sense to offer the same functionality for lists of entities. If you run
crm4.py and click on the Contacts menu item, you will see a list as follows:
You will notice that in the column containing the telephone numbers, those beginning with a plus sign are shown in a bold font. This will give a visible hint that this is probably a foreign number that needs some special code on your telephone switch.