If you're not HTML fluent you can do *bold* and _italics_ but you must use HTML for <strike>strikethrough</strike> or <u>underline</u>. You can also <deldelete<del><ins>insert<ins> or <em>emphasize<em> content, or make it <strong>strong</strong>.
The auto-format works more reliably when posting comments than diaries, though. And if you include any HTML you should make sure you set the appropriate pull-down menu to "HTML formatted" to avoid layout-wrecking extra whitespace. A vivid image of what should exist acts as a surrogate for reality. Pursuit of the image then prevents pursuit of the reality -- John K. Galbraith
Thank you for the help. In the end, might makes right. Nothing has changed since the caveman.