-<li><b>Coincident elements</b> is a list of groupes of elements for
-merging. All elements of each group will form one after the operation.
+
+<li>If the \b Manual Mode is selected, additional controls are
+ available:
+
+\image html mergeelems.png
+<br>
+<ul>
+<li>\b Detect button generates the list of coincident elements found
+ in the selected object.</li>
+<li><b>Coincident elements</b> is a list of groups of elements for
+ merging. As result of the operation all elements of each group will
+ be replaced by the firts element of the group.