diff --git a/cmd_parser.c b/cmd_parser.c
index 66b05bde..dc56b8b1 100644
--- a/cmd_parser.c
+++ b/cmd_parser.c
@@ -541,7 +541,7 @@ void parse_vlan(void)
 	}
 	return;
 err:
-	print_string("Error: vlan (<vlan-id>|show) [port][t/u]...\n");
+	print_string("Error: vlan (<vlan-id>|show) [port][t]...\n");
 }
 
 
diff --git a/doc/vlan.md b/doc/vlan.md
index a3d50c74..907f94be 100644
--- a/doc/vlan.md
+++ b/doc/vlan.md
@@ -69,9 +69,9 @@ void vlan_delete(uint16_t vlan) __banked;
 # VLAN configuration on the Serial Console
 For testing the following commands are provided on the serial console:
 ```
-vlan <VLAN-ID> p[t/u]...
-  create or set vlan with given ID and the list of ports as members, a t
-  behind a port defines the port as a tagged member, the u is optional
+vlan <VLAN-ID> p[t]...
+  create or set vlan with given ID and the list of ports as members, a `t`
+  behind a port defines the port as a tagged member.
 
 vlan <VLAN-ID> d
   deletes the VLAN