Notice this?

HTML input is enabled. Make sure you escape all HTML and angled brackets with < and >.

Auto-paragraphing is enabled. Double newlines will be converted to paragraphs; for single newlines, use the pre tag.

Allowed tags: a, abbr, acronym, b, blockquote, caption, cite, code, dd, del, dfn, div, dl, dt, em, i, ins, kbd, li, ol, p, pre, s, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, var.

For inputting literal code such as HTML and PHP for display, use CDATA tags to auto-escape your angled brackets, and pre to preserve newlines:

<pre><![CDATA[
Place code here
]]></pre>

Power users, you can hide this notice with:

.htmlpurifier-help {display:none;}