This case-sensitive code system http://hl7.org/fhir/list-mode defines the following codes:
Code
Display
Definition
working
Working List
This list is the master list, maintained in an ongoing fashion with regular updates as the real world list it is tracking changes.
snapshot
Snapshot List
This list was prepared as a snapshot. It should not be assumed to be current.
changes
Change List
A point-in-time list that shows what changes have been made or recommended. E.g. a discharge medication list showing what was added and removed during an encounter.