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    10 <!DOCTYPE concept

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

    12 <concept id="GUID-4C35C86A-D57F-503B-8E55-5D235E0D6DA0" xml:lang="en"><title>What

    13 is Versioning?</title><shortdesc>This topic describes the purpose and uses of versioning. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 

    15 

    16 

    17 <p>Tools and applications use a set of classes to represent the data in the

    18 Comms Database. These classes are the container classes, which derive from <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CMDBElement</apiname></xref> and <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>MMetaDatabase</apiname></xref>. </p>

    19 <p>The format of the data does not match the format of the data in the database.

    20 The implementation of the CommsDat API maps between the external format and

    21 the internal format. </p>

    22 <p>Future releases of Symbian platform can change the internal format. The

    23 map between the external format and the internal format maintains compatibility

    24 for tools and applications if the internal format changes. </p>

    25 <p>A new internal format is a new version of the interface. If a new version

    26 is created, the older version is deprecated, but Symbian platform maintains

    27 the compatibility for a managed period. </p>

    28 <p>You specify the version you need when you create a session with the Comms

    29 Database. </p>

    30 <p>A version is defined by an instance of the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>TVersion</apiname></xref> class. </p>

    31 <p>In practice, changes to versions are extremely rare. The curent version

    32 is the same version used when the Comms Database was added to Symbian platform. </p>

    33 </conbody></concept>