Tags and Attributes Deprecated in HTML 5
The following elements and attributes have been deprecated and therefore should not be used in HTML documents.
<a name>or<a id>withouthref<acronym>tag<applet>tag<bgsound>tag- the
marginheightandmarginwidthattributes of the <body> tag <center>tag<dir>tag<fn>footnote tag<font>and<basefont>tags<frameset>,<frame>and<noframes>tags- the
align,border,controls,dynsrc,hspace,loop,startandvspaceattributes of the <img> tag - inline style tags:
<big>,<blink>,<strike>,<tt>and<u> <isindex>tag<layer>,<ilayer>and<nolayer>tags<listing>tag<marquee>tag<nobr>tag<noembed>tag<noscript>tag<onreset>event attribute<plaintext>tag- the
languageattribute of the <script> tag <spacer>tag<xml>tag<xmp>tag
Other things to avoid in HTML
Here are some other things that should be avoided when coding HTML documents:
- The named non-breaking space HTML entity
should be avoided. The decimal entity or hexadecimal should be used instead. - The character sequence
]]>should be avoided unless it indicates the end of a CDATA section.