13.9.5 Quoting HTML tags
The HTML export back-end transforms ‘<’ and ‘>’ to ‘<’ and ‘>’. To include raw HTML code in the Org file so the HTML export back-end can insert that HTML code in the output, use this inline syntax: ‘@@html:...@@’. For example:
@@html:<b>@@bold text@@html:</b>@@
For larger raw HTML code blocks, use these HTML export code blocks:
#+HTML: Literal HTML code for export
#+BEGIN_EXPORT html
All lines between these markers are exported literally
#+END_EXPORT