Tagging allows discussions, libraries, and blogs to be organized and easily identified. When you click a tag on a discussion, library entry, or blog post, you'll be brought to a site-wide search repository of all of the other content that tag is applied to.
In the body of content (ie: blog article, discussion post, library entry), initiate the tagging process by clicking on the hashtag or by typing "#" and then start typing the keyword. As you type, a list of existing, suggested tags will appear. If you don't see the tag you are looking for, you can create your own new tag. You are able to add tags to your brand new post or you can reply to an existing post and add a tag in your reply.
Helpful tip: Do not use spaces when typing, as this will prevent hashtag creation. Also, if adding your own tag, press Enter to create it after spelling it out.