I thought this had been already implemented, but it seems this customization is only available in Plain skin.
With the attached util.js you can now add a label before a line in the Photodata template box to overwrite the default label:
Model=Iptc.Unknown tag (0x028f)
Download the attached util.js file and save it to the
skin directory (Ctrl-Shift-S) /
lib folder (overwriting the old one).