When a contact undergoes a change of address it is convenient to duplicate the contact and alter the address information in the duplicate to reflect the new information. The contact with the old information needs to remain in the database so as to retain historical information related to the old address, and keep new information related to the new address in invoices and reports.
In the Contacts window it is easy to differentiate between the old and new information because all of the information is visible on screen. But in the Invoice Edit and Report Edit windows, the contact information is selected from a list box which displays only the first and last name of the contact. In the case of duplicate contact names, you can't determine from the list box which entry is new and which is old.
Provide a field to contain a single-character code to differentiate between contacts with duplicate first and last names. This code could then display in the Contact list box appended to the name displayed to discriminate between which contact is being chosen for the Invoice or Report.