if($setName=='Dublin Core' && $elementName=='Medium')
{
$elementName="Summary";
}
I’m not sure where you got $label from? The above code in /omeka/themes/[yourtheme]/common/record-metadata.php will make it show
Summary
This is my summary
instead of
Medium
This is my summary
Make sure you put it before
<label><?php echo html_escape(__($elementName)); ?></label>