Encounter-closed - "Indicates the close of an encounter"

Is "close" synonymous with "end"? Is this trigger hit when the patient leaves the encounter (eg is discharged or the leaves an ambulatory facility) or is this about the administrative closing of an encounter (eg. all transcribed reports have been received, order lab tests have been resulted, charges have dropped)? Please clarify the meaning of "close" and if the first meaning is meant, "end" may be a better word to use as "close" often is interpreted as the latter.