format/formats attribute on alternate links

[hvdsomp]

The working draft uses format instead of formats in links in the HTTP Link header, e.g.:

Link:
  <http://example.org/resource/a>;
          rel="alternate";
          format="http://otherexample.org/profile/x",
  <http://example.org/resource/a>;
          rel="alternate";
          format="http://otherexample.org/profile/y",
  <http://example.org/resource/a>;
          rel="canonical";
          format="http://otherexample.org/profile/z"

The formats attribute is what is used by Mark Nottingham's Link Hint Internet Draft, which is leveraged in the Profile Negotiation I-D, which is, AFAIK, what the working draft is inspired by when it comes to profile negotiation.