Re: Valid CSS property "margin-block-start" not recognised

On 30 Sep 2019, at 10:52, roger morgan wrote:

> The validator generated the following error message for a document 
> containing the property margin-block-start, which has been in the 
> standard for years

It is not in any standard.

[MDN][1] says:

*This is an experimental technology*

and that it is defined in [CSS Logical Properties and Values Level 
1][2], the latest version of which says:

*This is a public copy of the editors’ draft. It is provided for 
discussion only and may change at any moment. Its publication here does 
not imply endorsement of its contents by W3C. Don’t cite this document 
other than as work in progress.*

[1]: https://developer.mozilla.org/en-US/docs/Web/CSS/margin-block-start
[2]: https://drafts.csswg.org/css-logical/#propdef-margin-block-start