HTML being stripped out

The Pootle page builder editor works in the same way as the default WordPress Editor when dealing with HTML. 

That is to say, only the following HTML elements are permitted within the editor. 

<strong>, <b>, <em>, <i>, <u>, <span>, <p>, <ol>, <ul>, <li>, <h1>, <h2>, <h3>, <h4>, <h5>, <h6>, <p>, <div>, <a[href|name]>, <sub>, <sup>, <strike>, <br>, <del>, <table[width]>, <tr>, <td[colspan|rowspan|width]>, <th[colspan|rowspan|width]>, <thead>, <tfoot>, <tbody>

If elements other that these are used then they are automatically stripped out.