missing </aaa> before <bbb>

Cause:

A closing tag </aaa> is missing before the opening of another tag <bbb>. This is probably due to a implicit close of the <aaa> tag due to the opening of the <bbb> tag.

Sample : missing </font> before <p>

There are 2 types of tags in the body of a HTML file, inline and block tags.
In the following sample, the <font> tag is an inline tag defined as containing only inline tags. But the <p> tag is a block tag. So,
- a <p> tag can not be contained in a <font> tag.
- when seeing a <p> tag the font tag is implicitely closed.

BAD     <font size=2><p>abc</p></font>

GOOD    <p><font size=2>abc</font></p>
  or    <p style="font-size: 80%">abc</p>
  or    <div style="font-size=80%><p>abc</p></div>

In the following sample, <font> tag should be contained in a <p> tag and not the opposite. Also, a better way to define the graphical look of a HTML page is to use Cascaded Style Sheet and use HTML only for the content.

References:

None