g an argument like
"<code>-EXIF:WhiteBalance=Manual</code>".</p>

<p>If a tag is added to a group that doesn't exist, the new group is created in
the file, and required mandatory tags may be created.  Conversely, if the last
non-mandatory tag is deleted from a group, the group is removed from the file.</p>

<a name='Mandatory'></a>
<h3>Mandatory Tags</h3>

<p>The EXIF and IPTC standards both specify some mandatory tags.  ExifTool will
automatically create many of these mandatory tags as required when writin