Versions of Endnote prior to 10 allowed the use of user defined fields, is this still possible?
Also, is it possible to use Endnote to populate a Word document with specific user defined fields?
There are still 8 custom fields, although all but the 8th custom field has been used (electronic article is one of the most flagrant “users” of these fields) in other styles, so you need to check your specific reference type for their availabilty (or to repurpose any field that you feel is superfluous). You edit a reference type from the preferences settings in Endnote.
There are also 3 “undefined” reference types, which can be used to create a new reference type from scratch (also created in the preferences settings>reference types).
Once you define a field for a specific reference type, you then can use it to modify the bibliography or citation template to incorporate the field information in your output style or output styles. This is done thru the edit>output styles in Endnote.