Labels can be added to a page, blog post, or attachment to help in the organization of your Wiki content. Users can search based on labels, browse all pages with a certain label, or even create RSS feeds to follow certain labels.
When a label is added to a page, it will be viewable by all users who have access to that space. Any user with permission to edit a page can add a label. Labels can only be a single word. To create labels with multiple words, use underscores between the words.
If you have the access to add labels to a page, you will see a pencil icon at the bottom of the page like this:
When you click the pencil icon, a box will appear that you can use to add or remove labels. When you're done adding labels, click the "Add" button. If you'd like to delete a label that's been added, click the X to the right of the label text.
When you close the box, you will see a list of labels associated with the page or blog post. You can click the pencil to return to the edit label screen above, or you can click on a label to show all pages associated with that label.