I imagine most of the web dev world hadn't realized that the display module of CSS3 was only in working draft status. There are some serious improvements and equally serious issues involved with this seemingly innocuous property.

I've taken the liberty of copying a letter to the whatwg and html5wg from the css3 wg. This is informative reading and well worth your time. Don't tl;dr the message.



Sep 27 (1 day ago)

to www-style, Boris, public-cssacc, whatwg, public-html, List, Daniel
About a fortnight ago, the CSS WG published an updated Working Draft of
the CSS Display Module L3:


CSS Display describes how the CSS formatting box tree is generated from the
document element tree and defines properties that control the types of boxes
thus generated.

Significant changes since CSS2.1 include:

* Splitting 'display' into 'display-inside' and 'display-outside'
to independently control the layout mode inside the box and its
role in the parent formatting context, respectively.

* Adding an independent "noneness" switch that does not overwrite
the box type declaration. (This will make it way more straightforward
to dynamically show/hide content.)

* Reintroducing 'display: run-in', but with more reasonable behavior
(as in, you can better reason about it. yay!)

* Adding a 'display: contents' value that eliminates the element's
own box and brings its children up to act as children of its
parent box.

* Adding a handy glossary of key terms from CSS2.1 chapter 9.

Significant changes since the previous draft are listed at:


We have a couple of key issues open that we would particularly like
feedback on:

A. Naming of the box-hiding-and-showing property. Please send us
suggestions for improvement! (Or comments on what you like about
the current name. We're pretty unsure atm, but want it to be
easily understandable.)

B. Run-in model: we're looking for a review by Boris Zbarsky Wink and
also for comments on how best to handle out-of-flow elements between
run-ins that form a sequence.

C. Interaction of 'display: contents' and counter numbering:
specifically, comments from implementers about the implementability
of various options, and comments from authors about how they'd expect
the numbering to behave.

D. Figuring out an ideal interaction for the new show/hide switch
and its equivalent (the 'speak' property) from CSS Speech.
(Likely we'll make 'auto' depend on the value of 'box-suppress',
but we're open to other considerations.)

Our plan going forward is to
1. resolve all the open issues (obviously)
2. defer the longhands of 'display' to another level [1]
3. hopefully transition to CR in the next six months

Please send any comments to the archived www-style mailing list,
, and please, prefix the subject line with


(as I did on this message). Also, please start a new thread; don't
reply to this one.

[1] It was a good exercise to split them, since we now have a properly
combinatorial understanding of how the various aspects of 'display'
interact. We plan to split them out again in a future level. But
there are combinations--like table cell flex containers--to this
that are very difficult to implement atm, and we can disallow at
a syntactic level if we retain only the shorthand 'display'. (The
show/hide switch, not being a longhand of 'display', will stay

For the CSS WG,



That came through on my

That came through on my twitter feed the other day, quite interesting and reminds us that this property has always had a depth that is easily overlooked for 'block' or 'none'.

Pleased to see display: run-in; make a comeback (if indeed it ever went away)

Splitting 'Display' into two contexts made me stop and think.

But most of all I was interested in and a little uncertain about the #box-suppress and it's usage.

run-in interests me too

Firefox did support run-in for quite a while, but dropped it when 1) tests continued to show that only a small number of tests in the suite were properly rendered by any browser. (IE may never have supported it; my memory is hazy. Firefox tested the best of the big four, now three since Opera adopted Webkit.) 2) Firefox, which supported run-in as early as v.2 gave it up due to a) a lack of support by other vendors, b) no clear specs on how it should work and c) no clear specs on how sibling inline and block elements should interact*.

Many of the new values have merit. I loved run-in and am glad to see it return. Hide/show or whatever it gets called has good points that will make scripting more robust. The inline-list-item value is something we should have had long ago.

The work of the CSSWG is a whole lot more valuable than much of the HTML5WG's redundancies and sometimes just plain silliness. I'm looking forward to general adoption by the various vendors.



* Which is why

<div>some bit of text
  <p>And a righteous contained paragraph.</p>
is not a good idea. ~gt

I should add

These display module properties and values are going to require careful study in order to fully grok their strengths and weaknesses; not to mention the gotchas and the size of the teeth thereof.

There are still humongous numbers of "web designers" whose buttocks resemble those of the companion of Candide's love, brought on by a poor understanding of the position property.


Not sure to what you allude

Not sure to what you allude in that last paragraph but have no doubt you're right!

As for bare naked text, we've never done that but then we're righteous Smile .

I have yet to see/read anything that explains the thinking / proposed practise behind the box-suppress notion but sure it makes sense.

Agree on the merits of CSSWG over the HTML5 one, HTML5 still bothers me greatly and still can't accept the section element as being useful or any of the new elements really, some of the element atts make sense though.

Still I do hope that somehow someone comes up with some means of making the whole process of WG work smoother and a LOT faster.

Voltaire's "Candide"

In Voltaire's "Candide", the love of Candide's life, Cunégonde, after many misadventures, is traveling with an old woman who had faced starvation. The party with which she shared this travail decide her buttocks were large enough they could slice a bit off each day and feed everyone until they could find other victuals.

Thus do the dangerous gotchas carve chunks from the nether regions of the unwary, and poorly taught web developers.

I am dismayed the the literary allusions so effortlessly rose above your capabilities of understanding.



Dismay thee not, I am of the

Dismay thee not, I am of the wit dim at best of times but French Novellas trying to pass themselves off as works of great literature ?


However the metaphor of gotcha munched buttocks and the slices of ham in Voltaire's middle-school level writing seemed especially connected.

It seems any wretch pushing an agenda, philosophical, political, economic or otherwise writes dreck. The French almost have the franchise on deep-thinking schlock; Voltaire, Sartre and de Sade come immediately to mind. What the heck, though. If you can dredge up a quote here or there, you look so much more erudite. Educated beyond your IQ, as I heard climate scientists described. Smile



Yep dropping quotes does ramp

Yep dropping quotes does ramp up the erudition factor.