You can configure the area settings to determine whether you wish to overwrite matched attributes in cases when only one is allowed per record.

When multiple attributes are allowed per record you can choose whether to  always add new attributes, only add if no existing match is found or do not add at all.

You can also specify which attribute settings to match on (description, date and/or comment).

Finally, you can opt to only add the attribute to new or existing Individual Relationships.