[css-overflow-3] Updated Working Draft of the CSS Overflow Module Level 3

The CSS Working Group has published an updated Working Draft of the CSS =
Overflow Module Level 3.

    https://www.w3.org/TR/css-overflow-3/

This module contains the features of CSS relating to scrollable overflow =
handling in visual media. This level is focused on completing a precise =
specification for the existing overflow features, including the =
'overflow' property and its longhands; 'line-clamp', its longhands, and =
its legacy pre-standard syntax; and the 'text-overflow' property. A few =
additional features introduced in support of the CSS Containment Module =
(see https://www.w3.org/TR/css-contain-2/) are also defined: 'overflow: =
clip' and the 'overflow-clip-margin' property.

It has been quite a while since the last update, so there is a fair =
amount of changes. The main changes can be broadly grouped in 3 =
categories:

 * More details about what is and isn't included in the scrollable =
overflow of a box. These changes are driven by trying to find the best =
balance between desirable behavior and compatibility constraints.

 * Significant revisions to the definition of the 'line-clamp' property =
and its longhands. The behavior is more precisely defined, takes into =
account ease-of-implementation concerns raised by interested browser =
vendors, and covers compatibility with the pre-standard =
'-webkit-line-clamp' property. Implementation experience is still =
limited, but the design is considered roughly complete. Detailed review =
and feedback is strongly encouraged at this point.

 * Introduction of the 'overflow-clip-margin' property, which determines =
how far outside its bounds the element is allowed to paint before being =
clipped when using 'overflow: clip' or the related 'contain: paint' from =
the CSS Containment Module (https://www.w3.org/TR/css-contain)

See the Changes section for further details:

    =
https://www.w3.org/TR/2020/WD-css-overflow-3-20200603/#changes-since-2018-=
07-31

Please send any comments to the mailing list <[email protected]>, =
prefixed with [css-overflow-3] (as I did on this message) or =
(preferably) file them in the GitHub repository at =
https://github.com/w3c/csswg-drafts/issues with the spec code =
[css-overflow-3] and your comment topic in the subject line.

For the CSS WG,
=E2=80=94Florian Rivoal=