if you happened to be creating a custom form and want to
create another field with the same name as a previously
created (although in a different form) you must delete it
out of the "user-defined fields in folder" field set
before you can create that same-name field via getting
out of the form, going to the custom-view properties of
the folder you're in, choosing to customize the field
shown, selecting the user-defined fields in folder option
towards the bottom, and selecting the field name of the
previous field with the same name and then selecting
delete\yes (p.371, 1st line, Outlook 2000 in a nutshell
by O'Reilly).