Wikipedia:Tip of the day/August 31
Category links work in a special way; they determine which categories an article shall belong to. The categories are displayed at the very bottom of the page, no matter where the link is inserted on the page.
Sometimes you may want to create a link to a category page without putting the current page in that category. This may arise on discussion pages or draft articles. To create such a link, place a colon (:) at the beginning of the link, like this: [[:Category:Physical exercise]], which shows up like this: Category:Physical exercise.
So if your link does not appear where you expected, it just means that you forgot the leading colon.
The same trick applies to links to Wikipedia in other languages. To create a visible link to the Indonesian Wikipedia article "Teknologi," use the id prefix for Indonesian, with a colon before it to keep it visible: [[:id:Teknologi]], which creates id:Teknologi.