Is space characters allowed or not allowed in id attr.?

[rniwa]

Hi,

In the spec of the id attribute, it says "The value must not contain any space characters." But then later it says "if the value is not the empty string, user agents must associate the element with the given value (exactly, including any space characters)." It sounds as if the spec. allows space characters to be present in the value of the id attribute.

It should be rephrased something like either "exactly, for historical reasons, including any space characters)" or just "exactly".

Or am I not understanding the spec?

[ahagen]

My interpretation is: including a space character in an id attribute results in the document not being valid HTML 5.

User agents must nevertheless match an id with space characters exactly, including the space characters. Even if the document is not valid HTML 5. In this way if the web author makes a mistake, the user agent provides a soft landing.