HTML Checking for Large Sites

The <table> element does not accept a height attribute. Use CSS instead.

A CSS definition for background-image could not be understood by the parser. Check its definition to ensure that it’s well formed and that it contains an appropriate value.

The specified CSS filter is not a standard one, and may only work in some browsers.

Check out the Filter Effects W3C Working Draft

Padding properties, unline margin properties, don’t accept negative values. Read more about the CSS box model

A CSS definition for an X property could not be understood by the parser. Check it to ensure that it’s well formed and that it contains an appropriate value.

<td> elements no longer accept an align attribute. This can be achieved using CSS like this:

<td style="text-align:center;">content</td>

<img> tags no longer accept a border attribute. This can be defined using CSS instead, for example:

<img src="..." alt="..." style="border:0;" />

The <center> tag is no longer valid in HTML, you should use CSS instead, for example:

<p style="text-align:center">this text will be centered</p>

The <font> element, used to define the font face, size and color in previous versions of HTML, is no longer valid in HTML5. Instead, you should rely on CSS styles.

For example, you can define a font size of 12px, bold text with inline styles like this:

<p style="font-size: 12px; font-weight: bold;">some text</p>

Learn more about CSS fonts:

• MDN: CSS font

<td> elements no longer accept a valign attribute. This can be achieved using CSS like this:

<td style="vertical-align:middle;">content</td>

Both <table> and <td> elements no longer accept a width attribute. Instead, you should use CSS as in this example:

<table style="width:100%;">

<tr>

<td style="width:50px;">Name</td>

</tr>

</table>

You’re using an attribute X that is no longer valid for element Y, but you can use CSS to achieve the same effect.