Annotation element removed from XSD 4.5b1?

Hello,

I am using Docbook XSD 4.5b1 and noticed that there is no longer an
annotation element (though there is a lineannotation for literal
content). I am wondering why the annotation element has been removed
or deprecated from Docbook 4.5b1 XSD (and possibly previous versions
of Docbook)? I'm fairly sure I saw an earlier reference to the
annotation element (was it in Docbook 3.x?).

Thanks,

-Serg