:dir lacks wide support

[r12a]

This issue is applicable to all languages with RTL orthographies.

Style sheets need to add special rules for RTL styles if they are not supported by logical properties or values.

One approach is to create a second style sheet which, when pulled into an HTML page, overrides styles in the main style sheet with settings for RTL text. This approach is not ideal because it requires maintaining the styles in two separate locations, which can therefore get out of synch, and it requires explicit addition of a call to the second style sheet in every page that will support RTL text.

The :dir() pseudo-class avoids these issues by allowing the content author to include the RTL variations in the same style sheet as the others. However, it is not yet supported by all major browser engines.

For more details, see this GitHub issue, which is being used to track this gap. Please add any discussion there, and not to this issue.

[r12a]

The first comment in this issue contains text that will automatically appear in one or more gap-analysis documents as a subsection with the same title as this issue. Any edits made to that comment will be immediately available in the document. Proposals for changes or discussion of the content can be made in comments below this point.

Relevant gap analysis documents include:
Adlam • Arabic/Persian • Hebrew • Kashmiri • N'Ko• Uighur