Roger is correct. The forum is capable of displaying a preview of certain urls. These include GitHub gists and Wikipedia articles, and I believe YouTube videos as well, perhaps others. If you post an appropriate link, a preview of the linked page will be displayed. For a gist, that's all of the code in the gist. For a Wikipedia article, that's the introductory section. (Or the section you link to, if you link to a specific section on the page.) Some API script writers opt to simply cost the code directly to the forum instead of hosting it on GitHub, which means a code block instead of a preview. Personally, I've had caching issues with gists posted to the forum, and occasionally have issues with the entire preview feature, so I often prefer having the code blocks directly. For one thing, if the connection is slow, the preview doesn't appear until after you've started reading, and then the posts jump down the page when the automatically-expanded preview shows up. Kitty's suggestion is to have a profile option to automatically show or hide these previews.