diff -r 66b0987716f9 -r dfd147de06b2 server/sources/rql2sql.py
--- a/server/sources/rql2sql.py	Thu Apr 15 18:54:13 2010 +0200
+++ b/server/sources/rql2sql.py	Thu Apr 15 19:39:55 2010 +0200
@@ -23,6 +23,12 @@
 Potential optimization information is collected by the querier, sql generation
 is done according to this information
 
+cross RDMS note : read `Comparison of different SQL implementations`_
+by Troels Arvin. Features SQL ISO Standard, PG, mysql, Oracle, MS SQL, DB2
+and Informix.
+
+.. _Comparison of different SQL implementations: http://www.troels.arvin.dk/db/rdbms 
+
 
 :organization: Logilab
 :copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.