Re: CSS1 compliance/support (was Re: @version rule)

On Sun, 29 Jul 2001, Tantek Celik wrote:
>> On Mon, 30 Jul 2001, Bjoern Hoehrmann wrote:
>>>>     Which level should IE6 claim to support?
>>> Microsoft claims full CSS Level 1 compliance (or support, don't
>>> know the exact wording).
>> I said _should_. I know Microsoft claim to have full CSS1 support.
>> I also know that unless their final release has significant
>> improvements over their last preview release, they are not even
>> close.
> I can only assume you are trolling Ian, so I'll bite. ;-)

Doh, I did say that I only picked IE6 at random!

>> Don't take this the wrong way, I'm very impressed by the
>> improvements that IE 6 Preview has over IE 5.5 in terms of CSS1
>> compliance. However, it is nowhere near the compliance of the best
>> browser(s) on the market, and those browser(s) rightly do not claim
>> full compliance.
> As measured by the W3C CSS1 Test Suite (the only official valid way
> to measure compliance to CSS1 - unless you have a better
> suggestion), IE6/Windows has full CSS Level 1 compliance,

I am aware of 6 CSS1 bugs in the last WinIE6 Preview release that are
visible in the CSS1 test suite.

> just as IE5/Mac did when it shipped over a year ago,

I am aware of 1 CSS1 bug in the MacIE5 release that is visible in the
CSS1 test suite.

> which was certainly not true for other browsers at the time (among
> others, the section 4.1.4 test [1] was particularly brutal, on even
> those browsers who at the time were claiming "superior
> conformance/compliance" - the results can be seen in Eric Meyer's
> leader board).

I am painfully aware of the many CSS1 bugs in Netscape 6.01 and
Netscape 6.1 Preview 1 that are visible in the CSS1 test suite. (I
can't give you an exact count since I don't track Mozilla's CSS1 test
suite bugs any closer than CSS1 bugs found in other test suites. But I
would guess there are between 1 and 6.)

On the plus side, Netscape 6.1 [3] passes the 4.1.4 test [1] with only
three bugs: there is very minor text overlap in the test after the 3rd
long rule separator, the floats are not placed high enough when they
are not at the immediate start of a line (as seen e.g. in the last
test), and 'clear' isn't applied to <hr> elements in quirks mode (that
last bug probably shouldn't be considered a bug, since it works in
standards mode -- the test suite triggers Netscape 6.x's quirks mode).

WinIE 6 Preview (6.0.2479.0006) has two bugs on this page: it doesn't
put text high enough (e.g. in the third test <div>, the first one
with the three floats), and it doesn't put floats high enough (the
same bug as seen in Netscape 6.1).

MacIE5 (2022) also has two bugs on this page: First, it has the same
text layout problem as WinIE6 on the third test <div>, and second it
puts unexpected spacing around the floats in that particular test.

> If other browsers pass the entire W3C CSS1 Test suite, then they too
> could claim a similar level of conformance.

Well. The CSS1 test suite doesn't test:

   1. 'float' with 'width:auto'
   2. the inline box model
   3. the background/border issue mentioned recently on this list

...all of which should IMHO quite significantly impact a claim of
"full CSS1 support".

Like I said, I am not in any way rubishing the efforts made by
Microsoft, or Opera, or Netscape, or any of the other browser makers
out there. I just have Issues with anyone who claims "full support"
merely on the basis of a basic test suite. I also have Issues with
people claiming that they fully pass the CSS1 test suite when they
don't, but I agree that it can be hard to be sure... ;-)

>> But then should IE6 claim to support to support 'ex'?
>> How about 'float'?
> Yes, see above. IE6/Windows passes the CSS1 Test Suite pages which
> test 'ex' and 'float'.

WinIE6 Preview fails both the 'ex' test [2] and the float test [1], as
does MacIE5.

-- References --
[3] Or, more precisely, a Netscape 6.1 internal candidate release
build. To reproduce these test results, you can compile and run the
Mozilla milestone from's CVS, since they have the
same rendering engine.

Ian Hickson                                            )\     _. - ._.)   fL
Invited Expert, CSS Working Group                     /. `- '  (  `--'
The views expressed in this message are strictly      `- , ) -> ) \
personal and not those of Netscape or Mozilla. ________ (.' \) (.' -' ______

Received on Sunday, 29 July 2001 23:48:04 UTC