{
  "id": "terminal-osc/2",
  "family": "terminal-osc",
  "slug": "2",
  "title": "OSC 2 — Set window title",
  "summary": "OSC 2 ; text ST sets ONLY the terminal window (tab) title to text, leaving the icon name unchanged. Written ESC ] 2 ; text ST (ST = ESC \\, BEL also accepted). Use this instead of OSC 0 when you want to set the window title without touching the X11 icon name.",
  "kind": "control-sequence",
  "aliases": [
    "set window title",
    "OSC 2",
    "ESC ] 2"
  ],
  "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 = 2 -> Change Window Title to Pt. (Ps = 1 changes icon name only.)"
    }
  ],
  "see_also": [
    "terminal-osc/0",
    "terminal-osc/7"
  ],
  "ext_type": "terminal-escape@1",
  "ext": {
    "csi_or_osc": "OSC",
    "command_number": 2,
    "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. Command number 2 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 window title",
        "meaning": "OSC 2 ; Pt ST sets the window (tab) title to the string Pt, without changing the X11 icon name.",
        "required": true,
        "byte_sequence_ST": "\u001b]2;mytitle\u001b\\",
        "byte_sequence_ST_readable": "ESC ] 2 ; m y t i t l e ESC \\   ==  \\x1b]2;mytitle\\x1b\\\\",
        "byte_sequence_BEL": "\u001b]2;mytitle\u0007",
        "byte_sequence_BEL_readable": "ESC ] 2 ; m y t i t l e BEL   ==  \\x1b]2;mytitle\\x07",
        "subparams": []
      }
    ],
    "gotchas": [
      "OSC 2 sets only the window title; OSC 0 sets both window title and icon name; OSC 1 sets only the icon name.",
      "Control characters in the title terminate the sequence early; sanitize the string before emitting.",
      "tmux/screen may need 'set-titles on' (tmux) to propagate child title changes to the outer terminal.",
      "No standard query form by default in xterm; title reporting is disabled for security unless allowWindowOps is set."
    ],
    "v1_smoke_test": {
      "asserts": "OSC 2 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"
}