• CellLabel is an option for Cell which gives the label to use for a particular cell.
• CellLabel->"" specifies that no label should be used for a cell.
• Cell labels are displayed when the setting ShowCellLabel->True is made.
• Cell labels are typically generated automatically when cells appear as input or output to the Mathematica kernel.
• Cell labels are automatically deleted when a cell is modified if CellLabelAutoDelete->True.
• New in Version 3.