--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/SDK/Source/GUID-C8C2645A-F5A4-53F0-8F43-485FC0B472DC.dita	Thu Jan 21 18:18:20 2010 +0000
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
+<!-- This component and the accompanying materials are made available under the terms of the License 
+"Eclipse Public License v1.0" which accompanies this distribution, 
+and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
+<!-- Initial Contributors:
+    Nokia Corporation - initial contribution.
+Contributors: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-C8C2645A-F5A4-53F0-8F43-485FC0B472DC" xml:lang="en"><title>External
+and internal representations</title><shortdesc>Describes the <codeph>Internalize()</codeph> and <codeph>Externalize()</codeph> functions
+for representing objects.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+<p>Since packages may be used to describe an object of any type, and may be
+conveniently written to a file and sent over communications links, it is tempting
+to use them to transmit all application data types.</p>
+<p><note>This is strongly discouraged in Symbian platform programming.</note> </p>
+<p>Packages directly package the <i>internal</i> representation of an object.
+They should only be used when the internal representation is expected by all
+recipients of the package. This would be the case, say, with inter thread
+data transfer or certain rare types of file.</p>
+<p>When an object is stored on file, or sent over a link, it is usually desirable
+to define an <i>external</i> representation which may be safely read by <i>any</i> Symbian
+platform implementation, even on a machine with different endianness, different
+compiler options, and different machine word size.</p>
+<p>In such a case, writing a struct directly is inappropriate. Instead, the <codeph>InternalizeL()</codeph> and <codeph>ExternalizeL()</codeph> functions
+should be implemented for the object and should encapsulate all internalisation
+and externalisation. The stream interface should be used, which may refer
+to file, communications, clipboard and a number of other possibilities.</p>
+</conbody></concept>
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