Re: [CSS21] out of range unicode escapes

On the I18N core, we have had some discussion on this topic, an this is the result of our discussion:

In http://lists.w3.org/Archives/Public/www-style/2007Apr/0045.html the
CSS WG propose replacing all out of range Unicode escapes with
the "replacement character" (U+FFFD).

This behaviour is not appropriate because U+FFFD is specified as a
Replacement Character to be "used as a substitute for an uninterpretable
character *from another encoding*".
see: http://unicode.org/glossary/#replacement_character .

The correct response to any invalid Unicode escape should be to treat it
as a parse error (see section 4.1.8), in the same way that any other
invalid or unexpected character would be.

For clarity Add this text to 4.1.3 at CSS 2.1 
http://www.w3.org/TR/CSS21/syndata.html#q6  :

    If the number is outside the range allowed by Unicode (e.g.,
    "\110000" is above the maximum 10FFFF allowed in current Unicode),
    then the parser should treat this as parse error and A user agent 
    must ignore a declaration containing this invalid property name or value.

see: http://www.w3.org/TR/CSS21/syndata.html#ignore

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David Clarke