HTML5 does not support purely expressive elements, framework-based elements, application elements, replaceable elements and old form elements. Detailed introduction: 1. Purely expressive elements, such as font, center, s, u, etc., these elements are usually used to control text style and layout; 2. Frame-based elements, such as frame, frameset and noframes, these elements are used in In the past, it was used to create web page layouts and split windows; 3. Application-related elements, such as applet, isinde, etc.

# Operating system for this tutorial: Windows 10 system, HTML5 version, Dell G3 computer.

HTML5 is a markup language for building web pages and applications that introduces many new elements and features to provide a richer and dynamic user experience. Although HTML5 supports many new elements, there are still some elements that are deprecated or no longer supported in HTML5. The following are some elements that HTML5 no longer supports:

Purely expressive elements: HTML5 no longer supports some purely expressive elements, such as font, center, s, u, etc. These elements are usually used to control text style and layout, but in HTML5, CSS should be used to achieve these effects.

Frame-based elements: HTML5 no longer supports some frame-based elements, such as frame, frameset, and noframes. These elements were used in the past to create web page layouts and split windows, but are deprecated in HTML5 and other methods should be used to achieve the same effect.

Application elements: HTML5 no longer supports some application-related elements, such as applets and isindex. These elements were used in the past to embed Java applets and create search engine indexes, but have been deprecated in HTML5 and other technologies should be used to achieve the same functionality.

Replaceable elements: HTML5 no longer supports some replaceable elements, such as acronym, big, strike, etc. These elements were used in the past to represent abbreviations, large text, and strikethroughs, but are deprecated in HTML5 and other markup or CSS styles should be used to achieve the same effect.

Old form elements: HTML5 no longer supports some old form elements, such as input elements whose type attributes are image, isindex, keygen, and textarea whose type attributes are textarea. elements etc. These elements were used in the past to create special types of form inputs, but have been deprecated in HTML5 and other form elements or JavaScript should be used to achieve the same functionality.

It should be noted that although HTML5 no longer supports the above elements, for backward compatibility, modern browsers are still able to parse and display these elements correctly. Therefore, in real-world applications, we can still use these elements in HTML5 documents, but it is recommended to use new HTML5 elements and functions as much as possible for better performance and user experience. At the same time, in order to ensure the accessibility and maintainability of web pages, the best practices and standards recommended in the HTML5 specification should be followed.

The above is the detailed content of What elements are not supported by html5. For more information, please follow other related articles on the PHP Chinese website!