Generally, programmers and Front End Engineers consider HTML a relatively easier language to learn. Yes, it is easier because you don't have to memorize thousands of language constructs and syntax. However, there are a few tags that are used very rarely which I am going to uncover today.
Specifies the base URL and/or target for the relative URLs on the page.
<head> <base href="https://ohmycheatsheet.com/images/" target="_blank"> </head> <p> <img src="demo2x2.jpg" width="100" height="104" alt="puzzle cube"><br /> <a href="/html/">HTML Code</a> </p>
Text that has been inserted.
<p>The Rubik's Cube World Record is <del>4.90</del> <ins>4.73</ins> seconds.</p>
Parameter for an object element.
<object data="sound.mp3"> <param name="autoplay" value="true"> </object>
<p>Normal text and <kbd>Keyboard input</kbd></p>
A Keypair generator field for forms. Not recommended to use because it's not supported in IE/Edge.
<form action="/action.php" method="post"> Name: <input type="text" name="name"> Encryption: <keygen name="encript"> <input type="submit"> </form>
See https://ohmycheatsheet.com/html-cheat-sheet/ for more.