This enumerated value records the method associated with this POST-code reference entry — how the catalog itself expects data for this code to be obtained when it fires. It sets an expectation an admin can check a real POST event's own method field against, to confirm whether a specific occurrence was captured the way the reference catalog anticipated. A reference method of 'direct hardware read' would mean any real occurrence of this code should likewise be reporting a directly-read value, not a cached or derived one.