Index: trunk/doc/user/06_feature/cam/index.html
===================================================================
--- trunk/doc/user/06_feature/cam/index.html	(revision 18268)
+++ trunk/doc/user/06_feature/cam/index.html	(revision 18269)
@@ -33,7 +33,7 @@
 <ul>
 	<li> @layername (e.g. "@top_copper" if the group's name is <i>top_copper</i>)
 	<li> location-type (e.g. "top-copper" for any layer group that is copper and is on the top side)
-	<li> type:offs (e.g. "copper:+2" means the second copper layer group from the top, "copper:-3" means the third copper layer group from the bottom)
+	<li> type:offs (e.g. "copper:+2" means the second copper layer group from the top, "copper:-3" means the third copper layer group from the bottom; offs is counted from 1, +1 meaning top outer layer, -1 meaning bottom outer layer)
 </ul>
 <p>
 (TODO: optionally prefixed with + or - for polarity and something for bloat/shrink)