The terms <user-defined fields> and <custom fields> refer the same thing – fields defined by a user that apply to a contact in addition to the standard Outlook fields.

However, for ease of reference, the term <custom fields> is used for those user-defined fields that are defined as part of a custom form.

There are some essential differences between <custom fields> defined in a custom form and <user-defined fields> used with contact items using the standard Outlook form (messageclass – <IPM.Contact>) some of which are:

An area that seems to confuse many people are user-defined fields in terms of where and when these get created. This article specifically addresses the topic from the standpoint of user-defined fields used when no custom form is in use (when the default MessageClass is <IPM.Contact>.

There are two separate and distinct (but related) groups of user-defined fields for Outlook contact items.

• <User-defined fields in folder>
• <User-defined fields in this item>