Proposal: display-order for serialization display order

NEED:
A property that sets the serialization display order of a selector within a 
parent element without affecting the document flow, independent of the 
source-code.

All current methods to achieve a comparable separation of style 
(position:absolute, position:relative, float etc) will take the selector out 
of the document flow and are therefore imperfect or sometimes unsuitable for 
any content with unknown dimensions: e.g. a table of contents of that is 
marked up (in the source) after the news-stories of march that it relates 
to. (As you'll never know how much news stories there will be for a month). 
It is then impossible to display the too tightly before the stories.

PROPOSAL:
display: inline | first
block | last
.... | before(id)
| after(id)
| number

As shorthand for the property display-order

BACKGROUND and BACKWARDS COMPATIBILITY:
Web developers want the main content in a document to be as close to the 
start of the document as possible for mainly two reasons:

1) Accessibility reason:
The nature of screenreaders forces serialization of a document - therefore 
the document will be read from start to bottom. Being able to change the 
order in which element displays will allow source-code to be optimized for 
both screenreaders and other browsers via media stylesheet.

2) (Minor) search engine optimization:
As content at the start of the document is perceived more important, this 
would improve search engine ranking.

Also independence from source-code order would achieve freedom for 
webdevelopers and remove practical limitations of CSS for layout.

Backwards compatibility:
Focus on implementing display-order first, then the display property. This 
way webdevelopers can incorporate display-order in their pages without 
worrying about their statement being ignored as 'invalid CSS' by error 
handling when used in display: property.


-- 
Best regards,
Sander van Dragt