[css-syntax] Reason for limited whitespace definition? #1654

css-syntax defines whitespace to include:

U+000A LINE FEED
U+000D CARRIAGE RETURN
U+000C FORM FEED
U+0009 CHARACTER TABULATION
U+0020 SPACE

Why not U+00A0 NO-BREAK SPACE or other Unicode WS characters?

In this Chrome issue a developer complained that someone found it confusing that what appeared to him like a space in his editor caused his CSS property to be ignored.