Automatic elimination of duplicates

When you import files and mark the box “discard duplicates” during importation, which fields does Endnote use to eliminate them? Is it the fields of author, title and year? Is it done by exact match?

Thank you!

By default, a reference is considered a duplicate when the Author, Year, Title, and Reference Type match a reference already in the library. Edit the preferences> duplicates settings, if you would like to change the duplicates criteria.  There is an option to ignore spacing and punctuation, but it won’t ignore initials/fullname or changes, like diacritics.