Option to Prevent Duplicate Data Deletion, or Alternate Data Sorting

Vacant land in some areas has an address of "0", like "0 Main St", because they've never had a structure requiring a street address. Sometimes I market specifically to vacant property owners, but because their addresses are all 0, the system will delete good leads when importing because they show up as duplicates if there is more than one vacant lot on the same street. There should be an option to turn off that feature for certain imports when there's different owner information, or have an option to upload by parcel number or some other unique identifier.