Internet Engineering Task Force (IETF) P. Saint-Andre Request for Comments: 6648 Cisco Systems, Inc. BCP: 178 D. Crocker Category: Best Current Practice Brandenburg InternetWorking ISSN: 2070-1721 M. Nottingham Rackspace June 2012 Deprecating the "X-" Prefix and Similar Constructs in Application Protocols Abstract Historically, designers and implementers of application protocols have often disting