What elements have disappeared in html?

Question

How and When is it used?

Answer 1

I am assuming that you are looking for the deprecated tags in HTML4, following is the list of the deprecated tags in HTML4. Not providing the detail (its easy to find)

<ISINDEX>...</ISINDEX>  
<APPLET>...</APPLET>  
<CENTER>...</CENTER>  
<FONT>...</FONT>  
<BASEFONT>...</BASEFONT> 
<STRIKE>...</STRIKE>  and <S>...</S>  
<U>...</U>  
<DIR>...</DIR>  
<MENU>...</MENU>