https://developer.mozilla.org/en-US/docs/Web/HTML/Element/marquee

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

https://www.w3.org/TR/2021/NOTE-html53-20210128/obsolete.html#the-marquee-element

11.3.1. The marquee element

The marquee element is a presentational element that animates content. CSS transitions and animations are a more appropriate mechanism.

https://en.m.wikipedia.org/wiki/Marquee_element

…The W3C advises against its use in HTML documents.