Checks whether the page boxes comply with the selected layout (Press, Screen viewing or PDF/X layout).
If you select this layout, the Action derives the correct media size from the first page box that is present in the document. The order in which is searched, is fixed: first the art box, then the trim, crop, bleed and finally the media box.
Screen viewing
If you select this layout, the Action checks if the page is defined solely by the crop box, which should have the same size as the media box. No other page boxes are allowed.
PDF/X layout
If you select this layout, the Action checks if the page box layout is compliant with the selected PDF/X version.
If you have chosen PDF/X-1a:2003 or PDF/X-3:2003, the art box or trim box shall not extend beyond the boundaries of the bleed box and the crop box.