Not CYRT, but the proper use of "semantic markup" means that it's easier for content to be programmatically understood for accessibility. By using HTML tags that sort of "call a duck a duck," things like screen readers can more easily understand how to process a document. H1-5 tags, for example, give an understanding of heading levels - 1 being the most important (usually the document title) and 5 being the least. They can be read differently than general body text and be jumped to by readers, as an example of how it can be more accessible.

For a longer write up, articles like the following can be helpful.
https://uxdesign.cc/semantic-html-the-foundation-of-web-accessibility-e5bbecad7c17