New answers tagged customization
Maybe something involving CellEpilog: SetOptions[ EvaluationNotebook, CellLabelAutoDelete -> False, CellEpilog :> SetOptions[EvaluationCell, CellLabel -> StringJoin["Kuba was here ", DateString]]] You can edit Stylesheet if you want to. I'm not sure if out could be modyfied this way too, but at the end ...
Go to Format -> Edit Stylesheet Under "Choose a style" choose "Output" Select the cell bracket of the new cell that appears Press Ctrl+Shift+E (Command+Shift+E on a Mac) to show the cell expression Change Cell[StyleData["Output"]] to Cell[StyleData["Output"], ShowCellLabel -> False] Press Ctrl+Shift+E again Close the stylesheet window
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