DOCS-5341 Clarify Replica Set Write Concern when w > 1 (#2620) (#2645)

* DOCS-5341 Clarify Replica Set Write Concern when w > 1

* JA edits + try reformatting

* adjust bullets

* AK edits + JA nit

* AK edits: more accurate language + clarify note on data-bearing members

* formatting

* typo fix

Author: ajhuh-mdb

source/core/replica-set-write-concern.txt

@@ -17,21 +17,22 @@ operation returns as successful. A member can only acknowledge a
 write operation after it has received and applied the write 
 successfully. 
 
-For replica sets, the default write concern of 
-:writeconcern:`w: 1 </<number/>>` requires that only the primary 
-replica set member acknowledge the write before returning
-write concern acknowledgment. You can specify an integer 
-value greater than ``1`` to require acknowledgment from the primary and 
-as many secondaries as needed to meet the specified value, up to the
-total number of data-bearing members in the replica set.
-
-Write operations with a write concern of :writeconcern:`"majority"`
-require acknowledgement that the write operations have propagated to a
-:ref:`calculated majority <calculating-majority-count>` of the
-data-bearing voting members. For clusters where members have :ref:`journaling
-<journaling-internals>` enabled, combining ``"majority"`` write concern
-with :writeconcern:`j : true <j>` can prevent :ref:`rollback
-<replica-set-rollbacks>` of write concern acknowledged data.
+For replica sets: 
+
+- The default write concern of :writeconcern:`w: 1 <\<number\>>` only requires 
+  acknowledgment from the primary replica set member before returning 
+  write concern acknowledgment. 
+
+- A write concern with a numeric value greater than ``1`` requires 
+  acknowledgment from the primary and as many secondaries as needed to meet the 
+  specified value. The secondaries do not need to be voting members to meet the 
+  write concern threshold. The specified write concern value cannot be greater 
+  than the total number of data-bearing members in the replica set. 
+
+- A write concern of :writeconcern:`w: "majority" <"majority">` requires 
+  acknowledgement that the write operations have been durably committed to a
+  :ref:`calculated majority <calculating-majority-count>` of the data-bearing 
+  voting members. 
 
 For complete documentation on write acknowledgment 
 behavior, see :ref:`wc-ack-behavior`. 

source/reference/write-concern.txt

@@ -98,11 +98,13 @@ available:
 
        ``w`` greater than 1 requires acknowledgment from the primary
        and as many data-bearing secondaries as needed to meet the
-       specified write concern. For example, consider a 3-member
-       replica set with a primary and 2 secondaries. Specifying ``w:
-       2`` would require acknowledgment from the primary and one of the
-       secondaries. Specifying ``w: 3`` would require acknowledgment
-       from the primary and both secondaries.
+       specified write concern. The secondaries do not need to be 
+       voting members to meet the write concern threshold. 
+       
+       For example, consider a 3-member replica set with a primary and 2 
+       secondaries. Specifying ``w: 2`` would require acknowledgment from the 
+       primary and one of the secondaries. Specifying ``w: 3`` would require 
+       acknowledgment from the primary and both secondaries.
 
        .. note:: 
 
@@ -120,9 +122,9 @@ available:
 
    * - .. writeconcern:: "majority"
 
-     - Requests acknowledgment that write operations have propagated to
-       the :ref:`calculated majority <calculating-majority-count>` of the
-       data-bearing voting members (i.e. primary and secondaries with
+     - Requests acknowledgment that write operations have been durably committed 
+       to the :ref:`calculated majority <calculating-majority-count>` of the 
+       data-bearing voting members (i.e. primary and secondaries with 
        :rsconf:`members[n].votes` greater than ``0``).
 
        For example, consider a replica set with 3 voting members,