Markup comprises of set of symbols, or a language, that can be used to provide instructions. HTML includes markup (programming code) to identify the structural elements of a document. Markup provides instructions to the software used for viewing a webpage on how the page should look and work. For example, the <p> element identifies a paragraph and <h1> identifies a first-level heading. Other elements would include lists, tabulated data, anchors, images and quotations.

Objective:

Screen readers use structural elements to help make reading a web page more efficient. For example, some screen readers can skip from heading to heading to allow the user to "skim" the document.

Guidelines:

• Identify section headings, paragraphs, lists, quotes, etc. using the appropriate tags instead of relying on formatting commands to distinguish these elements. For example, use <h1> tags to identify top-level headings rather than simply applying font-size or bold formatting commands
• Do not misuse structural elements for formatting effects, such as using < h1 > to make text bold or < blockquote > to indent a paragraph that is not actually a quotation
• < h1 > should be the first header on the page and subsequent headers should follow the logical order

Validation Technique:

Use W3C Markup Validation service