Index: trunk/doc/developer/alien_formats/io_altium/binary.txt
===================================================================
--- trunk/doc/developer/alien_formats/io_altium/binary.txt	(revision 35597)
+++ trunk/doc/developer/alien_formats/io_altium/binary.txt	(revision 35598)
@@ -76,7 +76,7 @@
 		- for copper layers (@228=0), check offs (@226):
 			- 1 is top copper
 			- -1 is bottom copper
-			- anything from 2 is intern copper, offset is 
+			- anything from 2 is intern copper, offset is offs-1 from top copper
 		- for non-copper layers (@228=3), check offs (@226):
 			6 = top silk
 			7 = bottom silk