YouTipThe WHO was founded in 1948.
``` --- ## Browser Support | Element | Chrome | Edge/IE | Firefox | Safari | Opera | | :--- | :--- | :--- | :--- | :--- | :--- | | `` | Yes (All) | Yes (IE 7+)* | Yes (All) | Yes (All) | Yes (All) | *\*Note: Internet Explorer 6 and earlier versions do not support the `` tag.* --- ## Definition and Usage The `` tag represents an abbreviation or acronym. ### Key Features: * **The `title` Attribute:** It is highly recommended to use the global `title` attribute with ``. The value of this attribute should contain the full, expanded version of the abbreviation. * **User Interaction:** When a user hovers their mouse pointer over the element, most modern desktop browsers display the expanded text as a tooltip. * **Accessibility (SEO & Screen Readers):** Providing the full expansion helps search engines index your content accurately and assists screen readers in pronouncing or explaining the abbreviation to visually impaired users. --- ## HTML 4.01 vs. HTML5 There are no functional differences for the `` tag between HTML 4.01 and HTML5. However, in HTML5, the `` tag completely replaces the obsolete `` tag, which is no longer supported. --- ## Attributes ### 1. Required/Recommended Attributes | Attribute | Value | Description | | :--- | :--- | :--- | | `title` | *text* | Specifies the full description or expansion of the abbreviation. This is displayed as a tooltip when hovering over the element. | ### 2. Global Attributes The `` tag supports all (https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes) (e.g., `class`, `id`, `style`, `lang`, etc.). ### 3. Event Attributes The `` tag supports all (https://developer.mozilla.org/en-US/docs/Web/HTML/Element/abbr#events) (e.g., `onclick`, `onmouseover`, etc.). --- ## Code Examples ### Example 1: Standard Usage with Tooltip This example shows how to define multiple abbreviations in a paragraph. ```htmlWe use HTML to structure web pages and CSS to style them.
``` ### Example 2: Styling the `` Tag with CSS By default, many browsers style `` elements with a dotted bottom border. You can customize this behavior using CSS: ```htmlThe NASA headquarters is located in Washington, D.C.
``` --- ## Best Practices and Considerations * **First Occurrence:** It is best practice to write out the term in full the first time it appears on a page, followed by the abbreviation in parentheses, like this: *World Wide Web (WWW)*. For subsequent occurrences, you can use `WWW`. * **Mobile Devices:** Tooltips triggered by the `title` attribute are generally not accessible on touch-screen devices (like smartphones and tablets) because there is no hover state. Do not rely solely on the `title` attribute for critical information. * **Do Not Use ``:** In older HTML standards, the `` tag was used for acronyms (abbreviations pronounced as words, like "NATO"). This tag is obsolete. Use `` for both abbreviations and acronyms.