Here's how to create a hastag in Facebook...
1. Use the # to create your own hastag
Anyone can make anything into a hashtag by adding a # in front of a word, acronym or phrase with no spaces. On Facebook, this is no different. As soon as you use the # symbol a blue box will appear over your tag. Then click Post. Your tag will appear in bold within your status update. Remember that hastags only work without spaces and special characters are not allowed.
2. Click your hastag
Once your post is published, you can click on your hastag to see who else is using that same phrase and what they are saying. For instance, clicking on #welcometofbookmastery will show up all of our posts on FB.
3. Search for hastags
Facebook is tracking those hashtags people are using, so a feed is always available even if you've not previously used the tag in a Facebook status update of your own. Simply type the tag of your choice, such as #cats, and click the page labeled Hashtag. This will open the same feed of related posts as you would get if you clicked on a hashtag in a post.