diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index edc9be92a6..697146468c 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -19186,7 +19186,7 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
         <indexterm>
          <primary>pg_create_physical_replication_slot</primary>
         </indexterm>
-        <literal><function>pg_create_physical_replication_slot(<parameter>slot_name</parameter> <type>name</type> <optional>, <parameter>immediately_reserve</parameter> <type>boolean</type>, <parameter>temporary</parameter> <type>boolean</type></optional>)</function></literal>
+        <literal><function>pg_create_physical_replication_slot(<parameter>slot_name</parameter> <type>name</type> <optional>, <parameter>initialize</parameter> <type>boolean</type>, <parameter>temporary</parameter> <type>boolean</type></optional>)</function></literal>
        </entry>
        <entry>
         (<parameter>slot_name</parameter> <type>name</type>, <parameter>lsn</parameter> <type>pg_lsn</type>)
@@ -19194,9 +19194,11 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
        <entry>
         Creates a new physical replication slot named
         <parameter>slot_name</parameter>. The optional second parameter,
-        when <literal>true</literal>, specifies that the <acronym>LSN</acronym> for this
-        replication slot be reserved immediately; otherwise
-        the <acronym>LSN</acronym> is reserved on first connection from a streaming
+        when <literal>true</literal>, specifies that the <literal>restart_lsn</literal>
+        for this replication slot be initialized immediately with REDO
+        <acronym>LSN</acronym> of the last checkpoint; otherwise it is
+        initialized on first connection from a streaming
+
         replication client. Streaming changes from a physical slot is only
         possible with the streaming-replication protocol &mdash;
         see <xref linkend="protocol-replication"/>. The optional third
diff --git a/src/backend/replication/slotfuncs.c b/src/backend/replication/slotfuncs.c
index 2806e1076c..703b61768b 100644
--- a/src/backend/replication/slotfuncs.c
+++ b/src/backend/replication/slotfuncs.c
@@ -43,7 +43,7 @@ Datum
 pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
 {
 	Name		name = PG_GETARG_NAME(0);
-	bool		immediately_reserve = PG_GETARG_BOOL(1);
+	bool		initialize = PG_GETARG_BOOL(1);
 	bool		temporary = PG_GETARG_BOOL(2);
 	Datum		values[2];
 	bool		nulls[2];
@@ -67,7 +67,7 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
 	values[0] = NameGetDatum(&MyReplicationSlot->data.name);
 	nulls[0] = false;
 
-	if (immediately_reserve)
+	if (initialize)
 	{
 		/* Reserve WAL as the user asked for it */
 		ReplicationSlotReserveWal();