Per http://lists.debian.org/debian-boot/2005/10/msg01407.html and followups, I've arranged for strings for apt-setup's Ubuntu mirror generator to be added to the d-i translation master files at the next update. They're not too different from the normal strings, and I made sure to put translator comments in the additional templates to say that they're only used in a derived distribution.
Christian Perrier and Frans Pop suggested that I post a short message to -i18n to explain the situation, hence this mail. Thanks, -- Colin Watson [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]

