HTML and CSS Reference
Drafts, which are subject to change, should not be used, unless you want to participate in the standards development
as a first implementer . Since these technologies are at varying degrees of adoption and standardization, web site
functionality cannot be guaranteed and the markup cannot be validated with full certainty (or validators provide this
feature as an experimental tool only). User experience might degrade due to nonworking components, users might
be prompted to download files of unknown types, and so on. Functionality and usability are more important than the
incorrect use of the latest, often nonfinalized specifications (Figure 12-1 ).
Figure 12-1. Modern markup applied incorrectly. What is the point?
Naturally, web designers cannot fall behind if they want to remain competitive, but they should not rely on
unofficial resources such as blog posts. Convincing clients and decision-makers to use the right standards can also be
a challenge when it comes to the well-underestimated Web Quality Assurance and strict timeframes.
Creating a standard-compliant web site with valid markup, styles, semantic content, and accessible code should be
the preferable way to develop a web site. You can verify whether individual technologies are standard-compliant
by validating the markup, the style sheet, and further components such as the feed channel during development.
However, the full standards compliance of a whole web site is more complex than that. As discussed throughout this
book, full standards compliance covers valid character encoding declaration (preferably UTF-8), valid HTML or valid
XHTML markup (the stricter, the better), valid CSS, valid RSS or valid Atom news feed, valid RDF, valid metadata, valid
XML, valid object embedding, valid script embedding, WCAG 2.0 and Section 508 conformance, accessibility, mobile-
friendliness, the application of Semantic Web technologies, browser- and resolution-independent code, and proper
server settings, just to mention the most important ones.