http://www.rfc-editor.org/rfc/rfc4034.txt
RFC 4034: Resource Records for the DNS Security Extensions, R. Arends, R. Austein, M. Larson, D. Massey, S. Rose2005-03-01T23:00:00-00:00 This document obsoletes RFC 2535 and incorporates changes from all updates to RFC 2535. [STANDARDS-TRACK]