Three New Tags

<small> Small Tag </small>

The small tag makes text appear smaller than the surrounding text. You use an opening and closing <small> tag around the text you want to make appear smaller. It is typically used for footnotes, disclaimers, copyright notices, side comments, etc.

Please note the example below:
Normal sized text. Small text

The code that produced the output above looks like this:
Normal sized text. <small>Small text</small>

I found this tag at W3Schools

<mark> Mark Tag </mark>

The mark tag highlights text, with a yellow background by default. You use an opening and closing <mark> tag around the text you want to highlight. You can use CSS (ex: style="background-color: green; color: white;") to change the color of the hightlight and text.

Please note the example below:
Hightlighted text Highlighted text with CSS

The code that produced the output above looks like this:
<mark>Hightlighted text</mark> <mark style="background-color: green; color: white;">Highlighted text with CSS</mark>

I found this tag at GeeksForGeeks

<details> Details Tag </details>

The details tag creates a section that you can expand or collapse to view content. You use an opening and closing <details> and <summary> tag. The summary tag creates the label or heading that you click to open or close the section.

Please note the example below:

The code that produced the output above looks like this:
<details>
<summary>Details</summary>
This text expands when you click the details section above.
</details>

I found this tag at MDN Web Docs