diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 3b33549a5715289311f4d384a758c15eb00b3cd0..9f9f9c533f41c041dbcdc4ad398eda3a4c73934f 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -557,6 +557,8 @@ const char *const config_group_names[] =
 	gettext_noop("Write-Ahead Log / Archiving"),
 	/* REPLICATION */
 	gettext_noop("Replication"),
+	/* REPLICATION_SENDING */
+	gettext_noop("Replication / Sending Servers"),
 	/* REPLICATION_MASTER */
 	gettext_noop("Replication / Master Server"),
 	/* REPLICATION_STANDBY */
@@ -1918,7 +1920,7 @@ static struct config_int ConfigureNamesInt[] =
 	},
 
 	{
-		{"wal_keep_segments", PGC_SIGHUP, REPLICATION_MASTER,
+		{"wal_keep_segments", PGC_SIGHUP, REPLICATION_SENDING,
 			gettext_noop("Sets the number of WAL files held for standby servers."),
 			NULL
 		},
@@ -1986,7 +1988,7 @@ static struct config_int ConfigureNamesInt[] =
 
 	{
 		/* see max_connections */
-		{"max_wal_senders", PGC_POSTMASTER, REPLICATION_MASTER,
+		{"max_wal_senders", PGC_POSTMASTER, REPLICATION_SENDING,
 			gettext_noop("Sets the maximum number of simultaneously running WAL sender processes."),
 			NULL
 		},
@@ -1996,7 +1998,7 @@ static struct config_int ConfigureNamesInt[] =
 	},
 
 	{
-		{"wal_sender_delay", PGC_SIGHUP, REPLICATION_MASTER,
+		{"wal_sender_delay", PGC_SIGHUP, REPLICATION_SENDING,
 			gettext_noop("WAL sender sleep time between WAL replications."),
 			NULL,
 			GUC_UNIT_MS
@@ -2007,7 +2009,7 @@ static struct config_int ConfigureNamesInt[] =
 	},
 
 	{
-		{"replication_timeout", PGC_SIGHUP, REPLICATION_MASTER,
+		{"replication_timeout", PGC_SIGHUP, REPLICATION_SENDING,
 			gettext_noop("Sets the maximum time to wait for WAL replication."),
 			NULL,
 			GUC_UNIT_MS
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index fa67e7a3d5c47e367266c3f9ba35fe4fbcee0d25..037316e727aa47b782f4d75b21f4ac82dcac6a30 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -194,19 +194,24 @@
 # REPLICATION
 #------------------------------------------------------------------------------
 
-# - Master Server -
+# - Sending Server(s) -
 
-# These settings are ignored on a standby server
+# Set these on the master and on any standby that will send replication data
 
 #max_wal_senders = 0		# max number of walsender processes
 				# (change requires restart)
 #wal_sender_delay = 1s		# walsender cycle time, 1-10000 milliseconds
 #wal_keep_segments = 0		# in logfile segments, 16MB each; 0 disables
-#vacuum_defer_cleanup_age = 0	# number of xacts by which cleanup is delayed
 #replication_timeout = 60s	# in milliseconds; 0 disables
+
+# - Master Server -
+
+# These settings are ignored on a standby server
+
 #synchronous_standby_names = ''	# standby servers that provide sync rep
 				# comma-separated list of application_name
 				# from standby(s); '*' = all
+#vacuum_defer_cleanup_age = 0	# number of xacts by which cleanup is delayed
 
 # - Standby Servers -
 
diff --git a/src/include/utils/guc_tables.h b/src/include/utils/guc_tables.h
index d3b25812a02866bf6dbabe373592de31f88e3509..84e9fb54d2fe87817988a9e4261f841678e0c2eb 100644
--- a/src/include/utils/guc_tables.h
+++ b/src/include/utils/guc_tables.h
@@ -69,6 +69,7 @@ enum config_group
 	WAL_CHECKPOINTS,
 	WAL_ARCHIVING,
 	REPLICATION,
+	REPLICATION_SENDING,
 	REPLICATION_MASTER,
 	REPLICATION_STANDBY,
 	QUERY_TUNING,