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... ISOC has obtained ownership of the IETF Contribution itself, which is
retained by the author(s) or remains in the public domain, as
applicable.
...
... a work of authorship is created (but see Section 8 below regarding
public domain documents), and IETF cannot make use of IETF
...
...
Certain documents, including those produced by the U.S. government
and those which are in the public domain, may not be protected by the
same copyright and other legal rights as other documents.
Nevertheless, we ask each Contributor to grant to the IETF ...