Go on to your username's global.js page and type this in.

window.announcementsIgnore =
    { option: 'opt-in-all',
    exceptWikiIds: [

    ] 
};

To follow announcements of certain wikis, go to Special:Version and find the number to the right of the Internals box, (E.g. this wiki would be 177) and type that number on the line between the two square brackets. Leaving it blank means that you'll be ignoring announcements from all wikis.

VersionCommunity Central