Do you validate your markup? How about your CSS? What about accessibility guidelines? Validating your code against the W3C validators can save time in creating cross-browser applications.
The W3C offers a QA matrix of popular specifications that the standards body recommends.
The list includes both recommendations and those specs that are in working draft.
The W3C (aka World Wide Web Consortium) is the standards organization for web development on the Internet. Some of the many features of the W3.org site include automatic validators and references for designers and browser developers.
Validating code can save time by immediately seeing all potential errors on a page that could be causing visual display problems when writing markup and CSS. It is important to validate both CSS and X/HTML markup in an effort to create a cross-browser, cross-platform web application.
There are other validators of importance that I use on a regular basis — including the Section 508 Accessibility guidelines recommended by the W3C. Some countries and states have passed laws for government sites and contractors working with governments forcing them to comply with at least one of the three levels of Accessibility.
Satisfying these guidelines and recommendations can ensure your web site works on all browsers, screen readers for the blind, and mobile phones.