Already described here: https://unix.stackexchange.com/questions/401744/how-to-turn-off-title-bar-window-numbering-in-kde KDE4-Bug: https://bugs.kde.org/show_bug.cgi?id=115540 When opening the same application twice, the title of the second window gets "<2>" as an appendix. The appendix stays, even if the first windows is closed. Many applications with splash screens always have the appendix, although there is only one open window. Therefore, it would be nice if there would be an option to reindex and update the window title everytime a window is closed.
If applications with splash screen get this numbering, it means the application don't mark their windows as splash screen. KWin does not workaround application bugs. In general this suggestion is not universally useful. It would mean that users cannot remember which window is which. There's a reason why the numbering doesn't change.
Thanks for your answer. I see your point about the splash screen. From my point of view, the current solution is not universally usefull too. 1. Open dolphin -> "Dolphin" 2. Open dolphin -> "Dolphin <2>" 3. Close "Dolphin" 4. Open dolphin -> "Dolphin" Now, the old window is "Dolphin <2>" and the new window is "Dolphin". This is confusing. I'd expect the newest window to have the highest number.