{
  "slug": "joliet",
  "term": "Joliet",
  "aliases": [
    "Joliet extensions"
  ],
  "definition": "Joliet extends ISO 9660 with a supplementary directory hierarchy containing big-endian UCS-2 filenames.",
  "note": "A Joliet volume retains a primary ISO 9660 hierarchy for readers that do not recognize the supplementary one. The 1995 specification allows a combined filename and extension budget of 128 bytes, representing 64 UCS-2 characters. UCS-2 on the disc is not UTF-8. [joliet-spec]\n\nFallback can expose different names. Joliet name support does not by itself preserve Rock Ridge permissions or symbolic links. Linux offers a nojoliet mount option and separate filename-encoding controls. Recovery checks should include names and required metadata as well as file bytes. [linux-isofs] [archive]",
  "related": [
    "iso-9660",
    "rock-ridge",
    "universal-disk-format",
    "optical-archival"
  ],
  "citations": [
    {
      "id": "joliet-spec",
      "title": "Ecma International: ECMA-119, 6th edition (2025), Annex C reproducing Joliet version 1 (1995)",
      "url": "https://ecma-international.org/wp-content/uploads/ECMA-119_6th_edition_december_2025.pdf",
      "accessed": "2026-10-21"
    },
    {
      "id": "linux-isofs",
      "title": "Linux v6.18 ISO9660 filesystem documentation: extension, permission and session options",
      "url": "https://www.kernel.org/doc/html/v6.18/filesystems/isofs.html",
      "accessed": "2026-10-21"
    },
    {
      "id": "archive",
      "title": "Hesela: optical archival storage and preservation checks",
      "url": "https://hesela.com/tech/optical-archival/",
      "accessed": "2026-10-21"
    }
  ],
  "provenance": [
    "Annex C of ECMA-119 (2025) faithfully reproduces Microsoft's Joliet version 1 specification dated 22 May 1995."
  ],
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-21"
}