HTML Checking for Large Sites

<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>

A <table> contains a <tr> row that has less <td> columns than the column count established by the first row. Check the table to ensure all rows have the same number of columns.

For example, in the following table, the first <tr> row defines that it’s 2 columns wide, but the second <tr> row tries to use only 1 column:

<table>
  <!-- This first row sets the table as 2 columns wide -->
  <tr>
    <td>First</td>
    <td>Second</td>
  </tr>

  <!-- This second row has only 1 column -->
  <tr>
    <td>Wrong</td>
  </tr>
</table>

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 value on the display property is not valid.

The display CSS property sets whether an element is treated as a block or inline element and the layout used for its children, such as flow layout, grid or flex.

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

font-display isn’t a CSS property, it’s a descriptor for use with the @font-face at-rule.

This issue is a false positive by the W3C validator, fixed in the latest versions of Nu Validator.

The value revert is indeed a valid value for the CSS property font-size.

The @import CSS rule can be used to import a style sheet into another style sheet. It must appear at the top of the document, and after any @charset declaration.