(X)HTML
HTML and XHTML are the markup languages used to create a solid foundation for your website or web application, and articles in this category generally touch upon the semantics and accessibility aspects of marking up web pages.
Use the fieldset and legend elements to group HTML form controls
Only use the fieldset and legend elements to group logically related form controls, always use both elements together, and keep legend texts short.
Using an XML declaration triggers Quirks mode in IE 6
If you use an XHTML doctype with an XML declaration, Internet Explorer 6 will switch to Quirks mode and use an incorrect CSS box model.
The evolution and future of HTML
Sam Ruby, co-chair of the W3C HTML Working Group, has put together a number of select quotes to illustrate the evolution of HTML, from the beginning to where it is now.
Use the p element to create paragraphs
Using p elements instead of multiple br elements to create paragraphs in HTML makes your documents more accessible and easier to style.
The alt attribute is for images only
The alt attribute is valid only for images and provides alternative text used when the image cannot be rendered. Do not use it with links and other non-image HTML elements.
It’s “class”, not “CSS class”
There is nothing called a “CSS class” in HTML or CSS, so please refer to values of the HTML class attribute as classes or class names instead.
Use CSS Diagnostics with Stylish to find bad HTML
Combining the concept of diagnostic CSS with the Stylish Firefox extension makes it easy to apply CSS that reveals invalid or deprecated HTML to any site you want.
Validating WAI-ARIA in HTML and XHTML
Validating WAI-ARIA in HTML or XHTML is currently more difficult than it could be, but it is possible and there is hope that it will be easier in the near future.
Creating valid names with the id attribute
There is a simple rule that defines which characters you may use with the id attribute: begin with a letter, then add any number of digits, hyphens, underscores, colons, and periods.
Headings, heading hierarchy, and document outlines
What do you do when an HTML document’s main heading is not the first text that should be marked up as a heading - insert a dummy heading or give up on having a perfect document outline?
Specify each HTML document’s main natural language
Always specify which natural language (spoken, written or signed human language) is used for a document’s content. Use the lang and/or xml:lang attributes for this.
Find inline CSS and JavaScript with Inline Code Finder
Inline Code Finder is a neat quality assurance tool that will find and highlight any elements that have inline events, inline styles, or javascript: links.
The id attribute’s value must be unique
The value of the id attribute must be unique in an HTML document. In other words, the same id value may only occur once.
Writing good alt text
It is quite common to come across images with missing alternative text or alternative text that does not properly describe the image’s content or function.
Validate an entire site with the Free Site Validator
The Free Site Validator crawls an entire site, validates all pages it finds with the W3C validator, and verifies all links it finds on the site.
Multiple form labels and screen readers
If screen readers reliably supported multiple labels for the same form control, it would be easier to make error messages and instructions fully accessible.
Validation statistics from Nikita the Spider
An analysis of the sites crawled by the bulk validation tool Nikita the Spider during March 2008.
Use the label element to make your HTML forms accessible
By using the label element to associate form controls with their label text, you improve the accessibility of HTML forms and make styling and scripting them easier.
POSH - Plain Old Semantic HTML
Teach people how to use plain old semantic HTML to create valid, well-structured, accessible and interoperable websites.
Understanding and extending semantics in HTML
John Allsopp on the current and possible future states of semantics on the HTML based Web.
