f either the IPTCDigest tag didn&#39;t exist
beforehand or its value agreed with the original IPTC digest (indicating
that the XMP is synchronized with the IPTC).  IPTC information is written
only if the original file contained IPTC.</p>

<p>Loading the MWG module activates &quot;strict MWG conformance mode&quot;, which has
the effect of causing EXIF, IPTC and XMP in non-standard locations to be
ignored when reading, as per the MWG recommendations.  Instead, a &quot;Warning&quot;
tag is generated when non-s