This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
According to the HTML spec per the content model for the option element, neither <option></option> nor <option label=""></option> are valid. I believe they should be valid, because: 1) there is widespread use of <option></option> on the internet, and 2) A (granted, non-normative) section of the select element describes setting the length attribute of a select element to add "new blank option elements to the select". There is no other definition of "blank option" and all current web browsers will generate "<option></option>" in response to increasing a select's length.
Moved to the HTML github: https://github.com/w3c/html/issues/176