1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

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     4 "Eclipse Public License v1.0" which accompanies this distribution, 

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     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-6D1A830E-F0F1-5C0F-8EEB-70922C0EF6B8" xml:lang="en"><title>Length,

    13 maximum length and size</title><shortdesc>Describes the length of 8-bit and 16-bit descriptors.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>A descriptor characterises the data it represents by the length of that

    15 data. The length of a descriptor is the number of data items it represents:</p>

    16 <ul>

    17 <li id="GUID-3AF8F237-CA2A-5AAF-A56E-ECC7C95907B7"><p>for 8 bit variant

    18 descriptors, the length is the number of single-bytes of data. When the descriptor

    19 represents non-Unicode strings, the length is the number of characters in

    20 the string.</p> </li>

    21 <li id="GUID-7610BC67-31CD-57DA-A72C-B1F4348C8FAC"><p>for 16 bit variant

    22 descriptors, the length is the number of double-bytes of data. When the descriptor

    23 represents Unicode strings, the length is the number of characters in the

    24 string.</p> </li>

    25 </ul>

    26 <p>The length of a descriptor cannot be greater than 2<sup>28</sup>.</p>

    27 <p>The size of a descriptor is the number of bytes occupied by the data represented

    28 by that descriptor:</p>

    29 <ul>

    30 <li id="GUID-830C6F31-EE2D-5C30-91D4-AB15FE4D2BA5"><p>for the 8 bit variant

    31 descriptors, the size is the same as the length.</p> </li>

    32 <li id="GUID-C7AF88D8-5836-53B9-A991-EA97B539C7CF"><p>for the 16 bit

    33 variant descriptors, the size is twice the length.</p> </li>

    34 </ul>

    35 <p>The descriptors which allow their data to be modified are also characterised

    36 by a maximum length. This represents an upper limit on the length of data

    37 the descriptor can represent, i.e.the length of data represented by the descriptor

    38 can vary can vary from zero up to, and including, this maximum value.</p>

    39 </conbody></concept>