"DebuggerStepIn" is a front end token that stops the evaluation at the next possible stopping point.

"DebuggerStep" is a front end token that stops the evaluation at the beginning of the next expression.

"DebuggerStepOut" is a front end token that stops the evaluation at the end of the current stack frame.

"DebuggerToggleBreakpoint" is a front end token that converts all messages generated during the evaluation into breakpoints.

"DeleteGeneratedCells" is a front end token that deletes all cells in the notebook that have been produced as output by the kernel.

"DuplicatePreviousInput" is a front end token that duplicates the contents of the nearest input cell above.

"DuplicatePreviousOutput" is a front end token that duplicates the contents of the nearest output cell above.

"EditStyleDefinitions" is a front end token that opens the Style Definitions dialog.

"EvaluateCells" is a front end token that sends the selected cells to the kernel for evaluation.

"EvaluatorHalt" is a front end token that interrupts the current evaluation and displays the evaluation stack.