[CSS21] Paged Media: page box initial size

Hello,

I seem to have lost the place where it is defined how to establish the
size of the page box (<http://www.w3.org/TR/CSS21/page.html>). I think
this used to be done with the 'size' property in CSS2, but this is no
longer in CSS21.

Would I use 'width' and 'height' properties in the @page rule?

Regards, Christian.