language_tags::GRANDFATHERED

pub const GRANDFATHERED: [(&'static str, Option<&'static str>); 26] = [("art-lojban", Some("jbo")),
                                                                       ("cel-gaulish", None),
                                                                       ("en-GB-oed",
                                                                        Some("en-GB-oxendict")),
                                                                       ("i-ami", Some("ami")),
                                                                       ("i-bnn", Some("bnn")),
                                                                       ("i-default", None),
                                                                       ("i-enochian", None),
                                                                       ("i-hak", Some("hak")),
                                                                       ("i-klingon", Some("tlh")),
                                                                       ("i-lux", Some("lb")),
                                                                       ("i-mingo", None),
                                                                       ("i-navajo", Some("nv")),
                                                                       ("i-pwn", Some("pwn")),
                                                                       ("i-tao", Some("tao")),
                                                                       ("i-tay", Some("tay")),
                                                                       ("i-tsu", Some("tsu")),
                                                                       ("no-bok", Some("nb")),
                                                                       ("no-nyn", Some("nn")),
                                                                       ("sgn-BE-FR", Some("sfb")),
                                                                       ("sgn-BE-NL", Some("vgt")),
                                                                       ("sgn-CH-DE", Some("sgg")),
                                                                       ("zh-guoyu", Some("cmn")),
                                                                       ("zh-hakka", Some("hak")),
                                                                       ("zh-min", None),
                                                                       ("zh-min-nan", Some("nan")),
                                                                       ("zh-xiang", Some("hsn"))]

Contains all grandfathered tags.