It is not suitable as currently defined in the model document.
Orientation has many uses. But as defined in the model document,
it is only for unpaginated document formats, such as text. We originally
had many attributes for text, such as margins, header-text, footer-text,
etc. We got rid of these many months ago. It doesn't make sense to
bring back just one of these.
When Roger described the reason for wanting this attribute, it was to
control 2-up so that the orientation would be right. Portrait page
images rotate 90 degrees counterclockwise and landscape page-images
rotate 90 degress clockwise. There is no issue for 1-up or 4-up because
they don't rotate. So, if this is the problem he is solving, he should
instead ask for an additional value called 2-up-landscape or
2-up-counter-rotate, whatever is his choice.
Bob Herriot