The list of HTML changes 5.1 stop the 5.2 is a bit extensive, but is documented, including showing the compatibility between browsers for each new implementation. You can see the full list here: https://w3c.github.io/test-results/html52/implementation-report.html
The List is divided into 3 parts. Altered Resources, Removed Features and Resources in Implementation.
This is just a bunch of Documented Changes, Check the rest on the link: https://w3c.github.io/test-results/html52/implementation-report.html
Interesting HTML 5.2 news
A new way of doing modals: Of all the novelties implemented with the new version of HTML, the introduction of the element <dialog> is by far the most interesting.
<dialog>
<h2>Cabeçalho do modal</h2>
<p>Conteúdo do modal, podendo incluir texto, imagens, links, vídeos etc.</p>
</dialog>
Multiple main elements: Previously, each web page could only contain one element <main> or would be found invalid.
Payment Apis in iframes
Styles in the body of the page: Although style settings are normally inserted in documents, from HTML 5.2 it becomes valid to define styles within the element <body> also, although the W3C itself does not recommend the practice.
<body>
<p class="azul">Texto azul!</p>
<style>
.azul { color: #0000FF; }
</style>
</body>
Headers in subtitles: From HTML 5.2, it is possible to enter headers (<h1> until <h6>) in elements <legend> form.
What becomes obsolete or invalid with HTML 5.2
The element <keygen>, previously used to generate public keys on forms has been removed from specifications.
The elements <menu> and <menuitem> also no longer part of the HTML specifications. They were used until then to create navigation menus or context.
From now on, the element <p> may contain only elements inline as valid children. That is, elements of the types inline-block, inline-table or block can no longer be nested within an element <p> semantically valid form.
Out of HTML 5.2
The elements <keygen>, <menu> and <menuitem>.
Inputmode attribute for elements <text> and the attributes of dropzone.
Method showModalDialog.
To API plugin was marked as obsolete.
The following constructs are now valid in HTML 5.2:
Use of the element <style> within the element <body>.
Multiple elements <main> in the DOM, provided that only one is visible to the user.
Possibility of having an element <div> as the child of an element <dl>.
Headers inside an element <legend> in a <fieldset>.
Source 1: https://imasters.com.br/desenvolvimento/html-5-2-o-que-nova-recomendacao-do-w3c-traz-de-novidade-para-o-desenvolvimento-web
Source 2: https://www.codigofonte.com.br/artigos/conheca-o-html-5-2
Version 5.1: This is the list of implementations of HTML 5.1 https://w3c.github.io/test-results/html51/implementation-report.html
Version 5.3 Draft: List of Drafts from HTML 5.3 https://www.w3.org/TR/html53/
