If highlighted, undoes the last action. If dimmed, the last action cannot be undone. Cut Cuts the selected text to the clipboard. Usually dimmed, because you cannot modify text in the Mosaic window. You can cut text from dialog boxes.
Copy Copies the selected text to the clipboard.
If the selected region include images, the images are not copied. Paste Pastes in text from the clipboard. You cannot paste text into the main Mosaic window, but you can paste text into the various fields in dialog boxes and the Annotation editing window. Clear Deletes the currently selected text. Does not work in the Mosaic window, because that text cannot be modified.