Index: trunk/doc/design/04_attrib.html
===================================================================
--- trunk/doc/design/04_attrib.html	(revision 3964)
+++ trunk/doc/design/04_attrib.html	(revision 3965)
@@ -123,12 +123,6 @@
 was affected by different sources of information. The complete
 compilation-history is stored in the source field, as an array (as specified below).
 
-<p>{des4:16} <a id="des4:16">
-For an attribute of a concrete object, the compilation-history should be a
-single item of file:line.column that indicates where exactly the attribute
-is declared. Line and column are optional and are usually omitted if the
-sheet has modifications in the memory compared to the version last loaded from
-a file. For new sheets not yet saved, the item shall be "&lt;not yet saved&gt;".
 
 <p>{des4:17}
 Attributes of abstract objects start with an empty compilation-history. Each
@@ -143,14 +137,23 @@
 of the information source and description is a short, free form text
 in which the source describes the reason for the change.
 
-<p>{des4:19}
+<p id="des4:16">{des4:16}{des4:19}
 Type and sources are specified in the following format:
 <ul>
-	<li> an attribute coming from the concrete model has "c" in type and
-	     the source shall be in <a href="#des4:16">file:line.column</a> format;
+	<li> an concrete attribute loaded from a file has "c" in type and
+	     the source shall be in <i>filename,line,col</i> format (,col is optional);
 	     description shall be empty
-	<li> an attribute generated by plugins has "p" in type and the source
-	     the view:plugin-name
+	<li> an abstract attribute coming from the concrete model has "ac" in type and
+	     the source shall be in <i>filename,oid-path,attr-key</i> format;
+	     description shall be empty
+	<li> type is  "pc" for an attribute generated by plugins from a concrete
+	     attribute, source is <i>filename,oid-path,attr-key,plugin-name</i>
+	<li> type is  "pa" for an attribute generated by plugins from an abstract
+	     attribute, source is <i>oid-path,attr-key,plugin-name</i>
+	<li> an attribute generated by plugins without attribute source
+	     has "p" in type and the source the <i>plugin-name</i> 
+	<li> (if multiple sources were used by a plugin, it needs to pick one main
+	     source and use one of the above three forms)
 	<li> if external tools modify the abstract model, the type shall be "e",
 	     and source shall be the name of the tool
 	<li> if the write failed a dash ("-") is appended to the type.