Are invalid attributes valid?

How bad is an invalid attribute? Robert Nyman asks the question and mentions the invalid attributes that .NET controls tend to output as an example of when you can live with a few harmless validation errors if the project deadline is so tight that you have to cut corners.

Obviously if there just isn’t time to fix errors that won’t prevent anyone from using the site, there may be more important things you should spend your time on. But I think that leaving invalid attributes in your markup is something you should think very carefully about, for several reasons:

In my opinion, leaving invalid attributes in your markup should be seen as a last resort.

Posted on October 11, 2005 in Web Standards