w=0	Unacknowledged	A write will not be followed up with a GLE call, and therefore not checked
w=1	Acknowledged	The write will be acknowledged by the (primary) server)
w=N	Replica Set Acknowledged	The write will be acknowledged by the primary server, and replicated to N-1 secondaries.
w=majority	Majority Acknowledged	The write will be acknowledged by the majority of the replica set (including the primary). This is a special reserved string.
w={tagset}	Replica Set Tag Set Acknowledged	The write will be acknowledged by members of the entire tag set
j=true	Journaled	The write will be acknowledged by primary and the journal flushed to disk