I've managed to update "pkrohn at daemonize dot com" array, after 12 years since initial publication.
If you want to change some of IPCT header-strings into something more human-readable, try to use array similar to this:
$iptcHeaderArray = array
(
    '2#005'=>'DocumentTitle',
    '2#010'=>'Urgency',
    '2#015'=>'Category',
    '2#020'=>'Subcategories',
    '2#040'=>'SpecialInstructions',
    '2#055'=>'CreationDate',
    '2#080'=>'AuthorByline',
    '2#085'=>'AuthorTitle',
    '2#090'=>'City',
    '2#095'=>'State',
    '2#101'=>'Country',
    '2#103'=>'OTR',
    '2#105'=>'Headline',
    '2#110'=>'Source',
    '2#115'=>'PhotoSource',
    '2#116'=>'Copyright',
    '2#120'=>'Caption',
    '2#122'=>'CaptionWriter'
);