Searching for cool HTML elements, especially if you don’t know what you’re looking for, is often like being thrown into a pile of garbage

Don’t worry, I did the dirty work for you!
After scavenging through the seemingly endless pile of HTML elements, I dug up a few of the rarely used gems!
1. meter & progress
The progress element is the semantically correct way of displaying progress bars.
The meter element is progress on steroids. Apart from displaying a scalar measurement within a known range, it allows you to specify the value's low, high & optimum range.
<meter min="0" max="100" low="25" high="75" optimum="80" value="50" ></meter>

2. sup & sub
You can add superscripts (like x²) with sup and subscripts (like x???) using sub to your document.