Index: doc/developer/dad/widgets.html
===================================================================
--- doc/developer/dad/widgets.html	(revision 21018)
+++ doc/developer/dad/widgets.html	(revision 21019)
@@ -184,7 +184,13 @@
 of is an integer index into that array, 0 being the first tab.
 
 
+<h3>PCB_DAD_DUP_ATTR(table, attr)</h3>
+<p>
+Create a new widget by duplicating an existing one. <i>attr</i> is the
+widget ID of the existing widget. If the widget being duplicated is a
+BEGIN*, it will need a corresponding PCB_DAD_END.
 
+
 <h2> Property sets </h2>
 
 #define PCB_DAD_COMPFLAG(table, val)   PCB_DAD_SET_ATTR_FIELD(table, pcb_hatt_flags, val | (table[table ## _len-1].pcb_hatt_flags & PCB_HATF_TREE_COL))