RFC 6648: Deprecating X-


Continuing the tradition I started earlier this year, here's a brief report on my latest document to be published in the RFC series. This one, RFC 6648, deprecates the convention of prefixing the names of experimental parameters with the special string "x-". As my co-author Dave Crocker put it, "x-" was a good idea whose time has passed. In theory it was a good idea to establish separate namespaces for standardized parameters and unstandardized parameters, but in practice the distinction was often moot anyway because some unstandardized parameters have a tendency to become widely adopted and thus leak into the space of standardized parameters. Although the "x-" convention has been around since 1975 and has made its appearance in application technologies as diverse as FTP, email, HTTP, MIME, LDAP, vCard, SIP, and XMPP, it has simply outlived its usefulness. This new RFC officially liberates developers from the shackles of "x-", so if you're working on applications that might need a new HTTP header or media type or vCard property or whatever, feel free to mint normal names like "foo" instead of "x-foo" (see the spec for examples and guidelines). I know I've already loosened the rules for XMPP parameters by updating XEP-0068: Field Standardization for Data Forms, and various RFCs might do the same thing for protocols and registries that still legislate the use of "x-" and similar constructs. Happy minting! :-)

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