Learn the HTML Elements Removed from HTML5
There are several HTML 4 elements that have been removed from HTML5. In order to use HTML5 correctly, you should stop using these elements.
In HTML 4 elements that removed from the specification are “deprecated,” but in HTML5 they are “obsolete.” The difference is that in HTML 4, deprecated elements should be removed from support by browsers. While in HTML5 obsolete elements are ones that may still be supported by browsers, but it that designers use other technology instead.
HTML Elements Removed from HTML5
acronymYou should use theabbrelement instead.appletInstead of this tag, you should use theembedelement or thevideoandaudioelements.basefontYou should set font properties with CSS.bigThis tag has no semantic value, and so you should define the styles in the CSS.centerYou should center with CSS.dirYou should use the appropriate unordered or ordered list instead.fontYou should set font properties with CSS.frameReplace frames withiframeor converted to non-framed sites.framesetReplace frames withiframeor converted to non-framed sites.noframesReplace frames withiframeor converted to non-framed sites.strikeReplace this tag with either theselement if the text is no longer accurate, with thedelelement if the text has been removed, or with CSS if the line through the text is just stylistic in nature.ttDefine the font styles with CSS.