The default editing mode is overstrike, which means that the characters you type replace the existing character at the cursor position. To change to Insert mode (in which the characters you type push existing characters to the right), press the Mode key for your keyboard.

When you are editing a report component, the current editing mode is displayed in the lower right corner of the frame.

When editing a report specification, you can only work on one line of trim at a time. Each line of trim is considered a separate component. You cannot extend or push a line of trim past the report's right margin, but you can use the Move operation to extend the report's right margin.