You can’t really tag third-party websites on Facebook, meaning the person or company has to have an official Facebook page. If they do, you can use the “@” command to mention them in posts, photos, or even comments. It’s pretty straightforward: 1. Go to your timeline and open the post you want to tag. 2. If it’s a photo, tap on the tag icon at the top of the screen. Then tap the part where you want the tag to appear and enter the page name. 3. If it’s a shared post or status update, tap the three horizontal dots in the upper-right corner. Enter the page name after the “@” symbol. Keep in mind that some pages don’t allow mentions nor tags.  If someone doesn’t want their profile or page appearing in your post, the Facebook link won’t work.