OSC 9 ; 3 Tab Title

OSC 9 ; 3 ; "text" ST sets the text of ConEmu’s tab to text, and an empty one puts back what the tab said before. It is not the window title, which OSC 2 sets.

It is one of the commands ConEmu, a Windows terminal, put under OSC 9; the progress report page lists them all, and their definition is the ConEmu specific OSC table in ConEmu’s documentation. iTerm2 uses OSC 9 ; text ST for a notification, and a terminal that has both tells them apart by what follows the 9.

A default xterm ignores all of OSC 9, which is not among the OSC numbers it knows. libghostty-vt recognizes it and does nothing with it, so neither shows anything.

Validation

CONEMU3-1: Nothing happens

A
\e]9;3;"tab"\a
B

|AB____|
cursor 1,3
title ""
reply none