OSC 1 Set Icon Name

OSC 1 ; Pt ST sets the window’s icon name, the label a window manager shows for it when it is iconified, and leaves the title alone. It is xterm’s, from dtterm, beside OSC 0, which sets both, and OSC 2, which sets the title. Sun’s and dtterm’s older form of it is OSC L Pt ST, with the letter L and no ;.

Unlike OSC 0 and OSC 2, a default xterm keeps only the low seven bits of each character of an icon name, so anything beyond ASCII comes out changed (doparsing). Few desktops show icon names now, and a case cannot see one: what it can see is that the title does not change.

libghostty-vt has no icon name, and ignores OSC 1, which leaves the title alone as xterm does.

Validation

OSC1-1: The title is left alone

\e]2;Window\a
\e]1;Icon\a

|___|
title "Window"

OSC1-2: Nothing on screen

A
\e]1;Icon\e\\
B

|AB_|
cursor 1,3