{
  "id": "terminal-osc/0",
  "family": "terminal-osc",
  "slug": "0",
  "title": "OSC 0 — Set icon name and window title",
  "summary": "OSC 0 ; text ST sets BOTH the terminal window title and the icon name (legacy X11 icon-name concept) to text. Written ESC ] 0 ; text ST (ST = ESC \\, BEL also accepted). The most widely supported of the title-setting OSCs.",
  "kind": "control-sequence",
  "aliases": [
    "set window and icon title",
    "set title",
    "OSC 0",
    "ESC ] 0"
  ],
  "status": "de-facto",
  "verification": "verified",
  "tier": "B",
  "source_url": "https://invisible-island.net/xterm/ctlseqs/ctlseqs.html",
  "source_version": "xterm ctlseqs, patch #410, 2026/04/19",
  "retrieved_date": "2026-05-29",
  "attribution": [
    {
      "claim_ref": "#summary",
      "source_url": "https://invisible-island.net/xterm/ctlseqs/ctlseqs.html",
      "source_version": "xterm patch #410, 2026/04/19",
      "note": "xterm ctlseqs 'Operating System Commands': Ps = 0 -> Change Icon Name and Window Title to Pt."
    }
  ],
  "see_also": [
    "terminal-osc/2",
    "terminal-osc/7",
    "terminal-osc/133"
  ],
  "ext_type": "terminal-escape@1",
  "ext": {
    "csi_or_osc": "OSC",
    "command_number": 0,
    "frame": {
      "introducer_7bit": "\u001b]",
      "introducer_7bit_readable": "ESC ] (0x1B 0x5D)",
      "introducer_8bit": "",
      "introducer_8bit_readable": "0x9D (single-byte OSC, 8-bit C1)",
      "note": "OSC frame per ECMA-48 5th ed. 1991 / ISO 6429. The command number 0 is an xterm convention with no formal registry."
    },
    "terminator": "ST|BEL",
    "terminator_detail": {
      "canonical_ST_7bit": "\u001b\\",
      "canonical_ST_7bit_readable": "ESC \\ (0x1B 0x5C)",
      "canonical_ST_8bit": "œ",
      "canonical_ST_8bit_readable": "0x9C (single-byte ST, 8-bit C1)",
      "alt_BEL": "\u0007",
      "alt_BEL_readable": "BEL (0x07)",
      "note": "ECMA-48 mandates ST; xterm and nearly all terminals also accept BEL. Emit ST, accept both."
    },
    "params": [
      {
        "id": "set",
        "anchor": "#set",
        "name": "Set icon name and window title",
        "meaning": "OSC 0 ; Pt ST sets both the window title and the X11 icon name to the string Pt. On modern terminals the icon-name concept is vestigial, so OSC 0 effectively just sets the window/tab title.",
        "required": true,
        "byte_sequence_ST": "\u001b]0;mytitle\u001b\\",
        "byte_sequence_ST_readable": "ESC ] 0 ; m y t i t l e ESC \\   ==  \\x1b]0;mytitle\\x1b\\\\",
        "byte_sequence_BEL": "\u001b]0;mytitle\u0007",
        "byte_sequence_BEL_readable": "ESC ] 0 ; m y t i t l e BEL   ==  \\x1b]0;mytitle\\x07",
        "subparams": []
      }
    ],
    "gotchas": [
      "OSC 0 sets BOTH window title AND icon name; use OSC 2 for window title only, OSC 1 for icon name only.",
      "The title string Pt must not contain control characters; in particular a BEL or ESC in the title will terminate the sequence early.",
      "Some multiplexers (tmux, screen) intercept and may rewrite or pass through title sequences depending on configuration (e.g. tmux 'set-titles').",
      "There is no query form for OSC 0/1/2 in xterm by default; title reporting is gated behind the 'allowWindowOps'/'disallowedWindowOps' resources for security reasons."
    ],
    "v1_smoke_test": {
      "asserts": "OSC 0 set form is a syntactically valid OSC string in both ST and BEL terminator forms.",
      "behavioral_conformance": "deferred to v2."
    }
  },
  "updated": "2026-05-29T00:00:00Z"
}