diff --git a/doc/docbook/system/mann/bb.xml b/doc/docbook/system/mann/bb.xml
index 3bb57053f8..724b07c74e 100644
--- a/doc/docbook/system/mann/bb.xml
+++ b/doc/docbook/system/mann/bb.xml
@@ -61,6 +61,14 @@
 	  </para>
 	</listitem>
       </varlistentry>
+      <varlistentry>
+	<term><option>-m</option></term>
+	<listitem>
+	  <para>
+	   Report the midpoint / center (x y z) of the bounding box.
+	  </para>
+	</listitem>
+      </varlistentry>
       <varlistentry>
 	<term><option>-o</option></term>
 	<listitem>
diff --git a/src/tclscripts/mged/help.tcl b/src/tclscripts/mged/help.tcl
index bd78a4ad3c..9fcf62eed2 100644
--- a/src/tclscripts/mged/help.tcl
+++ b/src/tclscripts/mged/help.tcl
@@ -62,6 +62,8 @@ Options:
 	-c bbname       Create an rpp primitive of the bbox named 'bbname'.
 	-d              Show bbox dimensions.
 	-e              Show bbox coordinates.
+	-m		Show the midpoint / center of bbox
+	-o		Calculate oriented bbox
 	-q              Do not print header.
 	-u              Use air.
 	-v              Show volume.