[css3-page] Outer Width/Height Inconsistency?

Hi,

http://dev.w3.org/csswg/css3-page/#max-margin-dimension


outer widththe sum of a margin box’s left and right margins, left and right
border widths, left and right padding, and content-box width. outer  
heightthe
sum of a margin box's top and bottom margins, top and bottom border widths,
used top and bottom padding, and content-box height.

For outer width "left and right padding" is added
where for outer height "*used* top and bottom padding" is added.

Is this intentional or an error?

Yuzo