How do I get rid of the unknown property name errors in Visual Studio?

When using jQuery UI and ThemeRoller the CSS files created contain several CSS properties that are not known by Visual Studio, such as zoom and opacity. How can I keep these from showing up as errors in the error list when the CSS file is open in the editor pane?

In the spirit of SO, I'll add the solution I found as a response.

From stackoverflow

• Go to Tools --> Options --> Text Editor --> CSS --> CSS Specific (or Validation) and uncheck the Detect unknown properties checkbox.