Maybe it should even be moved out of the Flexbox specification into one, which both specs refer to, maybe extend CSS Box Alignment's scope to cover it, or a totally new one that also includes z-index from CSS 2.

But I agree that as a first step, the Flexbox definition should include that it also applies to grid items.

Sebastian

CSS Display might be another candidate for the property, maybe a better fit than a stacking context or alignment spec.

To me, alignment seems a slightly better choice than display spec, because the behavior of order is affected by the display value of the container, not the elements themselves, similarly to how alignment properties are, and the alignment spec already has a section for the behavior of alignment properties in different formatting contexts/schemes. Or maybe visual and non-visual ordering of items is worth its own distinct module, perhaps combined with spatial navigation and related a11y aspects?

order reorders boxes, so CSS Box might also be a candidate.

The CSS Working Group just discussed Order property definition, and agreed to the following:

• RESOLVED: Move order property to Display module

In the discussion participants were biased by initially mentioning Display as the preferred spec. The alternatives (Alignment, Box, new spec.) were not discussed.

I don't have a strong opinion on that topic, though when making a decision all options should be considered.

Sebastian

Alignment is about the positioning of boxes relative to their containing blocks, and order has nothing to do with that. So I think it wouldn't make sense there.

CSS Box Model focuses on margins and paddings and defining the various box areas. I don't think order really fits into there either.

CSS Display focuses on the construction of the box tree, and order effectively reorders elements in the box tree. This is why I think it's the best fit.

Note the +1 from @rachelandrew, who teaches this stuff. If she felt it was an uncertain fit, I think she would not have marked +1.

@fantasai Thank you for the explanation for why you decided moving it to the Display module!

I previously wrote to extend the Alignment module to move it there, as I thought it would fit best there, or create a completely new spec. for it, but anyway, your explanation is fine for me.

Sebastian

Fixed in 0259f1f