Z-Index Relative or Absolute?

[Pontifex]

I'm trying to find an answer to the following question:Is an element's z-index style its absolute stack order, or its stack order relative to its parent?For instance, suppose I have the following code:\[code\]<div style="z-index:-100"> <div id="dHello" style="z-index:200">Hello World</div></div><div id="dDomination" style="z-index:100">I Dominate!</div>\[/code\]Which one will be in front - #dHello, or #dDomination?That's just for examples. I've tried this in multiple places and results seem to vary. I'm seeing if anyone knows of an authoritative source for settling:1) What are the actual standards regarding z-index (on this topic specifically)?2) How do individual browsers vary in their actual implementation of this?Thanks!