Preserved HTML Editor Markup is a WordPress plugin designed to maintain user-generated HTML markup in the TinyMCE editor, enabling seamless interaction between developers and end-users. Unlike many alternatives, this plugin allows users to work in the HTML tab while editors can simultaneously utilize the WYSIWYG Visual tab, ensuring that HTML markup remains intact during transitions. It supports HTML5 Block Anchor tags and offers full JavaScript code block compatibility, allowing for a more versatile editing experience. Installation requires careful attention to existing content to avoid rendering issues, with a dedicated Fix It Tools feature available to assist in this process.

The plugin has evolved through several updates, enhancing its functionality with options for inline CSS and JavaScript, as well as customizable tag behavior for newlines. Recent versions have addressed bugs and improved user control over content formatting. While it provides significant capabilities, users should be aware of some limitations, including specific behaviors related to script blocks and tag handling. Overall, Preserved HTML Editor Markup is a valuable tool for those looking to enhance their WordPress editing experience.