Index: trunk/doc/developer/io_lihata_ver.html
===================================================================
--- trunk/doc/developer/io_lihata_ver.html	(revision 19022)
+++ trunk/doc/developer/io_lihata_ver.html	(revision 19023)
@@ -60,6 +60,12 @@
 	Extended the text object fields with optional thickness and rot fields that
 	will be able to override the default mechanism for determining the thickness
 	or the n*90 degree rotation angle (with an arbitrary value).
+	<p>
+	New layer group types PCB_LYT_DOC and PCB_LYT_MECH are handled on load
+	and save.
+	<p>
+	The layer visibility bit is not saved any more - it was reset after load so
+	it only added noise to the file.
 
 </body>
 </html>
Index: trunk/doc/developer/lihata_format/comm_data.lht
===================================================================
--- trunk/doc/developer/lihata_format/comm_data.lht	(revision 19022)
+++ trunk/doc/developer/lihata_format/comm_data.lht	(revision 19023)
@@ -70,7 +70,7 @@
 						desc={a logical layer}
 						li:children {
 							ha:lid        = { valtype=integer;  ver={>=2} desc={layer ID}}
-							ha:visible    = { valtype=integer;  desc={only in real (non-boud) layers: 1 if the layer is visible, 0 if not (UI setting)}}
+							ha:visible    = { valtype=integer;  ver={<6} desc={only in real (non-boud) layers: 1 if the layer is visible, 0 if not (UI setting)}}
 							ha:group      = { valtype=integer;  desc={only in real (non-boud) layers: "parent" layer group ID }}
 							ha:color      = { valtype=string;  ver={>=5} desc={ layer color on UI, in #rrggbb format }}
 							ha:stack_offs = { valtype=integer;  desc={only in bound layers: match offset e.g. for internal copper layers}}