t() :: %Cldr.LanguageTag.U{
  calendar: atom(),
  cf: atom(),
  col_alternate: atom(),
  col_backwards: atom(),
  col_case_first: atom(),
  col_case_level: atom(),
  col_hiragana_quaternary: atom(),
  col_normalization: atom(),
  col_numeric: atom(),
  col_reorder: atom(),
  col_strength: atom(),
  collation: atom(),
  currency: atom(),
  dx: atom(),
  em: atom(),
  fw: atom(),
  hc: atom(),
  kv: atom(),
  lb: atom(),
  lw: atom(),
  ms: atom(),
  numbers: atom(),
  rg: atom(),
  sd: atom(),
  ss: atom(),
  timezone: atom(),
  va: atom(),
  vt: atom()
}