HTML Guide

Bad character “X” after “<”. Probable cause: Unescaped “<”. Try escaping it as “<”.

The < and > characters are reserved for HTML tags, so if you need to use them as content, they should be escaped as < and > respectively.

For example, to illustrate the mathematical truth that 1 < 2 in HTML, we can write it this way:

<p>1 &lt; 2</p>