diff --git a/patroni/config.py b/patroni/config.py
index 88efa057..99ce58f1 100644
--- a/patroni/config.py
+++ b/patroni/config.py
@@ -96,7 +96,7 @@ class GlobalConfig(object):
 
     @property
     def is_quorum_commit_mode(self) -> bool:
-        """:returns: `True` if quorum commit replication is requested"""
+        """:returns: ``True`` if quorum commit replication is requested"""
         return str(self.get('synchronous_mode')).lower() == 'quorum'
 
     @property
diff --git a/patroni/dcs/__init__.py b/patroni/dcs/__init__.py
index a50f3dce..36e91121 100644
--- a/patroni/dcs/__init__.py
+++ b/patroni/dcs/__init__.py
@@ -615,8 +615,9 @@ class SyncState(NamedTuple):
     :ivar version: modification version of a synchronization key in a Configuration Store.
     :ivar leader: reference to member that was leader.
     :ivar sync_standby: synchronous standby list (comma delimited) which are last synchronized to leader.
-    :ivar quorum: if the node from sync_standby list is doing a leader race it should
-                  see at least quorum other nodes from the sync_standby + leader list.
+    :ivar quorum: if the node from :attr:`~SyncState.sync_standby` list is doing a leader race it should
+                  see at least :attr:`~SyncState.quorum` other nodes from the
+                  :attr:`~SyncState.sync_standby` + :attr:`~SyncState.leader` list.
     """
 
     version: Optional[_Version]
@@ -1949,8 +1950,9 @@ class AbstractDCS(abc.ABC):
 
         :param leader: name of the leader node that manages ``/sync`` key.
         :param sync_standby: collection of currently known synchronous standby node names.
-        :param quorum: if the node from sync_standby list is doing a leader race it should
-                       see at least quorum other nodes from the sync_standby + leader list
+        :param quorum: if the node from :attr:`~SyncState.sync_standby` list is doing a leader race it should
+                       see at least :attr:`~SyncState.quorum` other nodes from the
+                       :attr:`~SyncState.sync_standby` + :attr:`~SyncState.leader` list
 
         :returns: dictionary that later could be serialized to JSON or saved directly to DCS.
         """
@@ -1967,8 +1969,9 @@ class AbstractDCS(abc.ABC):
         :param leader: name of the leader node that manages ``/sync`` key.
         :param sync_standby: collection of currently known synchronous standby node names.
         :param version: for conditional update of the key/object.
-        :param quorum: if the node from sync_standby list is doing a leader race it should
-                       see at least quorum other nodes from the sync_standby + leader list
+        :param quorum: if the node from :attr:`~SyncState.sync_standby` list is doing a leader race it should
+                       see at least :attr:`~SyncState.quorum` other nodes from the
+                       :attr:`~SyncState.sync_standby` + :attr:`~SyncState.leader` list
 
         :returns: the new :class:`SyncState` object or ``None``.
         """
diff --git a/patroni/postgresql/sync.py b/patroni/postgresql/sync.py
index 067583d7..169f5f00 100644
--- a/patroni/postgresql/sync.py
+++ b/patroni/postgresql/sync.py
@@ -354,7 +354,9 @@ END;$$""")
         for replica in sorted(replica_list, key=lambda x: x.nofailover):
             if sync_node_maxlag <= 0 or replica_list.max_lsn - replica.lsn <= sync_node_maxlag:
                 if self._postgresql.global_config.is_quorum_commit_mode:
-                    # add nodes with nofailover tag only to get enough "active" nodes
+                    # We do not add nodes with `nofailover` enabled because that reduces availability.
+                    # We need to check LSN quorum only among nodes that are promotable because
+                    # there is a chance that a non-promotable node is ahead of a promotable one.
                     if not replica.nofailover or len(active) < sync_node_count:
                         if replica.application_name in self._ready_replicas:
                             numsync_confirmed += 1
@@ -379,6 +381,9 @@ END;$$""")
 
     def set_synchronous_standby_names(self, sync: Collection[str], num: Optional[int] = None) -> None:
         """Constructs and sets ``synchronous_standby_names`` GUC value.
+        
+        .. note::
+            standbys in ``synchronous_standby_names`` will be sorted by name.
 
         :param sync: set of nodes to sync to
         :param num: specifies number of nodes to sync to. The *num* is set only in case if quorum commit is enabled