MS Outlook has auto complete feature which provide suggestions in pop-up window as you type. At times, auto complete suggestions may not be useful and you may want to edit offered suggestions.
By default you cannot edit values suggested by auto complete feature. However, portable tool NK2Edit provide easy way to edit and customize those auto complete values. You can easily modify or fix all information stored in the NK2 file, including the display name, the email address, the exchange string, the Drop-Down display name and the search string.