Straight from the latest HTML 4 spec: The META element can be used to identify properties of a document (e.g., author, expiration date, a list of key words, et

Straight from the latest HTML 4 spec: The META element can be used to identify properties of a document (e.g., author, expiration date, a list of key words, etc.) and assign values to those properties. No matter where you choose your source, meta elements apply to the document. The document is not the web site. It is an individual page such as a tweet, a user's profile, or the homepage. Is that authoritative enough?