Q:

markup validator on yahoo.com

About to release a web site to production and wanted to run this in http://validator.w3.org/. I get a bunch of errors, something like "reference not terminated by REFC delimiter", "reference to external entity in attribute value", etc etc, and some legitimate "required attribute alt is not specified" etc.
I wanted to see how other sites are doing, so I tried yahoo.com and I see twice the amount of errors on it.
What errors need to be corrected or should I even bother? Perhaps this is not really very useful?

A:

Validators are often useful for making sure that your HTML is rendered correctly across browsers, but that particular validator is not always up to date with the latest standards.
It will be much better in the future (for you and other developers on your project) if you try to correct as many of those errors as you can.

