Addded clarifications proposed by Federico Di Gregorio.

pep-0249.txt

@@ -198,7 +198,10 @@ Connection Objects
             forward; an Error (or subclass) exception will be raised
             if any operation is attempted with the connection. The
             same applies to all cursor objects trying to use the
-            connection.
+            connection.  Note that closing a connection without
+            committing the changes first will cause an implicit
+            rollback to be performed.
+
             
         commit()
           
@@ -232,7 +235,13 @@ Connection Objects
 Cursor Objects
 
     These objects represent a database cursor, which is used to
-    manage the context of a fetch operation.
+    manage the context of a fetch operation. Cursors created from 
+    the same connection are not isolated, i.e., any changes
+    done to the database by a cursor are immediately visible by the
+    other cursors. Cursors created from different connections can
+    or can not be isolated, depending on how the transaction support
+    is implemented (see also the connection's rollback() and commit() 
+    methods.)
         
     Cursor Objects should respond to the following methods and
     attributes:
@@ -243,7 +252,11 @@ Cursor Objects
             sequences.  Each of these sequences contains information
             describing one result column: (name, type_code,
             display_size, internal_size, precision, scale,
-            null_ok). This attribute will be None for operations that
+            null_ok). The first two items (name and type_code) are
+            mandatory, the other five are optional and must be set to
+            None if meaningfull values are not provided.
+
+            This attribute will be None for operations that
             do not return rows or if the cursor has not had an
             operation invoked via the executeXXX() method yet.