| Symbol | Value | Description |
|---|---|---|
HistoryPurgeTail | 0 | All phantom operations (or operation tail) are dropped and removed. |
HistoryPurgeBranches | 1 | All branches except the current one are dropped and removed. |
HistoryPurgeAllButCurrent | 2 | All operations in a history are deleted. The document state is NOT changed, all modifications are “merged” into the single operation, which becomes an operation list root. |
HistoryPurgeAll | 3 | Remove all operations except the very first one. |