ISSUE-147: [css3-syntax] CSS escape sequences

[css3-syntax] CSS escape sequences

Raised by:
Richard Ishida
Opened on:

From: Mathias Bynens <>
Date: Thu, 12 Jan 2012 11:35:48 +0100 defines CSS escape
sequences of the form `\000026` or `\26 `, both of which decode to

WebKit browsers don’t support this syntax for characters outside the
BMP: For example,
`\1d306 ` or `\01d306` are supposed to be escape sequences for the
“tetragram for centre” symbol (U+1D306), but they don’t work in

There seems to be another way to escape these characters, namely by
breaking them up in UTF-16 code units: `\d834\df06 `. All browsers
except Gecko (
seem to support this, even though this isn’t mentioned in the spec.

Should the spec be changed to reflect reality?
Related Actions Items:
No related actions
Related emails:
  1. Review of tracker issues for best practices (Part V) (from on 2015-04-09)
  2. [minutes] i18n telecon 2012-04-25 (from on 2012-05-02)
  3. Re: non-support of using surrogate pairs in CSS escapes [I18N-ACTION-90] [I18N-ISSUE-147] (from on 2012-02-01)
  4. Re: non-support of using surrogate pairs in CSS escapes [I18N-ACTION-90] [I18N-ISSUE-147] (from on 2012-02-01)
  5. non-support of using surrogate pairs in CSS escapes [I18N-ACTION-90] [I18N-ISSUE-147] (from on 2012-01-31)
  6. [minutes] i18n telecon 2012-01-25 (from on 2012-01-25)
  7. I18N-ISSUE-147: [css3-syntax] CSS escape sequences [CSS-mail] (from on 2012-01-20)

Related notes:

From Mathias Bynens:
"I’ve updated the WebKit bug asking to remove their support for
the non-standard syntax[1]. (FTR, here’s the WebKit bug regarding
support for standard CSS escape sequences for supplementary characters[2].)

I also closed the Gecko bug discussing whether or not to support
the non-standard surrogate-pair syntax[3] as invalid, filed Opera
bug DSK-356580, and IE bug 722267 asking to remove support for
the non-standard syntax[4]."

Ready to close.

Richard Ishida, 13 Apr 2012, 15:20:17

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