by benmc » Jan 22nd, '12, 05:43
welcome to Mageia
if you are referring to mozilla firefox and thunderbird, i have found that by going to: mageia control centre, , software management, install and remove software, enter programme name into search box [ in my case firefox ] . a list is generated for all search word matches, some of which will have a check mark beside them, uncheck those locales that are of no use to you and then "apply "bottom right of screen. at the next update only the remaining locale you have select should be updated. unfortunately you need do this for each programme.
i trust this is of use. other users may have a less cumbersome methodology.
regards
benmc