All the browsers do, partly.
 >  Who decided to specify
 > it in the SGML Declaration for HTML?
I did:
revision 1.5
date: 1994/05/17 21:07:49;  author: connolly;  state: Exp;  lines: +24 -4
        OMITTAG has been changed to YES for implicit </LI> etc. tags
        SHORTTAG has been changed to YES to support
                <DL COMPACT> and <IMG ALIGN=top>
        as short forms for
                <DL STYLE="COMPACT"> and <IMG ALIGN="top">
 >  Was this discussed much?
Not a whole lot.
But with SHORTTAG NO, you have to quote ALL attribute values.
<DL COMPACT> goes out the window. <IMG ISMAP> goes.
Dan