Originally Posted by Almiel
I found this (not sure if it applies to you): "Percentage values refer to the height of the containing block. If the height of the containing block is not specified explicitly (that is, it depends on content height), and this element is not absolutely positioned, the percentage value is treated as none." from http://reference.sitepoint.com/css/max-height
I also found this on the spec page
(thought I'd remembered seeing it): "Use of the CSS position property values to achieve absolute positioning (i.e. absolute and fixed) is strongly discouraged."
I am still learning
I assumed the block was: the display page: and I wanted the dingbat not to exceed 10% of available Height (780+px ) (actual size 298)
Sigil did the 10% scale.
None of the other viewers did that.
So I replaced the image (HARD to do in Sigil. Had to add the New one, then Global S+R the name change)