Index: gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.950
diff -u -p -r1.950 gdb.texinfo
--- gdb.texinfo	25 Apr 2012 16:13:17 -0000	1.950
+++ gdb.texinfo	27 Apr 2012 19:20:13 -0000
@@ -24580,7 +24580,11 @@ detailed technical information on @value
 stack.
 
 A @code{gdb.Block} is iterable.  The iterator returns the symbols
-(@pxref{Symbols In Python}) local to the block.
+(@pxref{Symbols In Python}) local to the block.  Python programs
+should not assume that a specific block object will always contain a
+given symbol, since changes in @value{GDBN} features and
+infrastructure may cause symbols move across blocks in a symbol
+table.
 
 The following block-related functions are available in the @code{gdb}
 module: