Custom Address Fields
If you scroll down to the bottom of the screen in the address window you will see some fields numbered ‘User’ 1 to 5. These fields don’t mean usernames, they are user defined fields. They are meant to be used for specific information about a contact but can’t fit it anywhere else, for example birthdays.
To use them, move the cursor on to the specific field and hit your wheel and select ‘Change Field Name’