The dupchk option ( duplicate checking) on the various import programs follows a very light matching logic.

If the profile is an Individual it matches on:
  • The first 2 characters of the first name ( if the name is greater than 1 character in both)
  • The middle initial ( if non blank in both)
  • The entire Last Name
  • The City

So this will mean that:
Stacy Smith, Steven Smith, Stanley J Smith, Stephanie K Smith are equivalent
John Peters in Concord NH will match Jorge W Peters in Concord CA

If an organization it matches the Organization and City. There is no fuzzy matching.  It is an exact character comparison.

So this will mean that "The National Zoo of DC" in Washington will NOT match "National Zoo of DC" in Washington nor "The National Zoo of the Capital" in Washington.
Bentley College will NOT match Bentley Coll
"The United Way" will NOT match "United Way"
"Univ of PA" will not match "Univ. of PA"