Delete A Cell

To delete a whole cell, select the cell in the hierarchy browser and choose "Delete Cell" from the context menu (right mouse button). This time, three possible modes are offered:

Shallow delete: Just the cell (it's shapes and instances) are deleted, not any cells referenced by this cell. Since cells might no longer be referenced after that, they may appear as new top cells in the layout.
Deep delete: The cell and all it's subcells are deleted, unless the subcells are referenced otherwise (by cells that are not deleted). In this delete mode a complete hierarchy of cells can be removed without side effects.
Complete delete: The cell and all it's subcells are deleted, even if other cells would reference these subcells.