The special message string 'translator-credits' should not be translated, but should instead contain the name(s) of the translator(s) of the current translation, separated by newline characters. E-mail addresses in <email address hidden> after the name are optional.
This string is used by GtkAboutDialog and GnomeAboutDialog (not sure whether it's also used in the KDE world) to display the translation credits in the about dialog. It's also used in Ubuntu documentation <https://launchpad.net/distros/ubuntu/breezy/+sources/ubuntu-docs/+pots/aboutubuntu/pt/+translate?offset=20>.
However, many translators don't know about this special string and just translate it into their language, which means that developers importing translations have to edit it manually, which is suboptimal. Even those translators who know how to edit it in Rosetta can't, because translators are supposed to be specified one per line, but Rosetta presents it as a single-line field.
Rosetta should handle this string automatically, and put the names of the contributors in there.