Re: [CSS21] zindex.html "element" terminology

On Mon, Jul 16, 2012, Anton Prowse wrote:

>D'oh!  Thanks for pointing that out.  I was aware of that in the
>past, but I certainly had forgotten that when working on Appendix E
>the other day.

I'm sure; I know you've looked in detail at that appendix in the past, it's
just a matter of working without context on a little bit of that chapter.

> ...although that special treatment doesn't actually help in any of
> the cases that I'm currently handling, because the only thing it
> does is to include /anonymous/ boxes under the umbrella of the word
> "element".  The boxes that I'm concerned about are never anonymous,
> ...
> Aside: in fact, I would argue that the marker box of a list item
> isn't anonymous either, so the example given in E.1 to illustrate
> the redefining of "element" isn't relevant.

I agree that the first sentence of this description of ‘element’ reads like a
strict definition that excludes non-anonymous boxes.  I too would say that
marker boxes aren't anonymous (as they have an associated element: "anonymous
box" is never formally defined in CSS 2.1, but §9.2.2.1 gives what looks like
the criterion), and I too had noticed the apparent conflict between first and
third sentences (in the sense that the first sentence seems to defines
‘element’ as excluding marker boxes while the third sentence seems to make
clear that marker boxes were intended to be included as "elements").  The
aforementioned "box that is a child of that element" phrase would also be
problematic if we take that first sentence as a strict definition.  I would
tend to conclude that the first sentence isn't actually a definition after all,
and is merely trying to convey loosely what's meant.  You can also see
something of that looseness in the preceding definition of "tree order",
defined in terms of "rendering tree" even though that term isn't defined
anywhere.

If we take the E.1 definition to be informal (or in error), and take that
third sentence to imply that ‘element’ does include non-anonymous boxes,
then the special treatment does help the cases you're looking at.

(Of course that interpretation still leaves us with an error in the spec
to fix.)

pjrm.

Received on Monday, 16 July 2012 15:12:45 UTC