Henri Sivonen wrote:
Since UAs handle whitespace in the id attribute inconsistently (see
below), old specs imply or require whitespace trimming and ids with
whitespace are unreferencable from whitespace-separated lists of ids, I
suggest adding the following language concerning document conformance:
The value of the id attribute must be a string that consists of one or
more characters matching the following production: [#x21-#xD7FF]|
[#xE000-#xFFFD]|[#x10000-#x10FFFF] (any XML 1.0 character excluding
whitespace).
I'd rather see the id attribute restricted to an NCName token insofar
as possible. We can make an exception for Hixie's repetition templates,
but otherwise I think it should be compatible with the XML ID syntax.
So
xsd:id {
pattern: "\S*";
}
The concept of "idness" is a useful one for many tools, and even if
browsers don't care what characters there are, other tools do. We can't
express IDness in a schema if we insist on ignoring its syntactic
restrictions.
~fantasai
