<!DOCTYPE para>
<para>
    The json-based data file can be stored in a version control system (vcs)
    like svn or git.

    <itemizedlist>
        <listitem>
            <para>
                Close the crystal-facet-uml application before synchronizing a file with your vcs.
                Do not synchronize the file with your vcs while you modify it at the same time.
            </para>
        </listitem>
        <listitem>
            <para>
                In case of merge conflicts in the json-based data files,
                note that uuid strings do uniquely identify all json objects.
                Relations between objects are defined by these uuid strings.
                In contrast to uuids, integer-id can be changed
                as long as they are unique among all objects of same type within the file.
                Also the names of classifiers (nodes) must be unique.
            </para>
        </listitem>
        <listitem>
            <para>
                To see the changes between versions of the json file, consider to use the patience option:
                <command>git diff --patience</command>
                The result may better explain the changes.
            </para>
        </listitem>
    </itemizedlist>
</para>
