David Klhufek

<p>This simple plugin adds useful buttons to the native WordPress HTML editor (Classic Editor).</p>
<p>Currently adds:<br />
h1, h2, h3, h4, h5, span, hr, nbsp, mox</p>
<p>The “mox” button adds a nice responsive CSS class which you can use to highlight pictures or other elements in your posts.</p>
<p><strong>Note:</strong> This plugin works only with the Classic Editor. It does not support the new Gutenberg (Block Editor).</p>
<h3>Compatibility</h3>
<ul>
<li>Requires the Classic Editor to be active.  </li>
<li>Designed specifically for the <strong>HTML mode</strong> of the editor.</li>
</ul>


Quicktags for WP

This simple plugin adds useful buttons to the native WordPress HTML editor.

Ecwid by Lightspeed Ecommerce Shopping Cart

<p>WordPress HTML editor (tinyMCE) treats schema.org attributes like itemscope/itemtype/itemprop as invalid HTML attributes and strips them when you save the post or page content. This plugin alters this behavior and prevent the WordPress HTML editor from removing the schema.org/microdata markup.</p>
<h3>Credits</h3>
<p>@azaozz suggested the solution. See the issue discussion here: https://core.trac.wordpress.org/ticket/27931</p>


Protect schema.org markup in HTML editor

Easy tool to stop HTML editor from removing schema.org/microdata tags from post or page content.

Quicktags for WP vs Protect schema.org markup in HTML editor