Source:http://linkedlifedata.com/resource/umls/id/C0392747
HL7V3.0: <p>Definition: Used to link a newer version or 'snapshot' of a business object (source) to an older version or 'snapshot' of the same business object (target).</p><p><i>Usage:</i>The identifier of the Act should be the same for both source and target. If the identifiers are distinct, RPLC should be used instead.</p><p>Name from source to target = "modifiesPrior"</p><p>Name from target to source = "modifiesByNew"</p>,NCI: The act of alteration or modification; changed or altered in form or character.