10. In a printing system of the type including means for advancing a receipt tape through a receipt tape zone and a printing mechanism for effecting printing along a printing path extending across the receipt tape zone and thereby printing on the receipt tape, the improvement comprising: means for positioning an alternative document in a zone overlying the receipt tape zone and including the printing path so that the printing mechanism prints on the alternative document instead of the receipt tape; and means responsive to the positioning of an alternative document to receive printing for advancing the alternative document with respect to the printing path; the means responsive to the positioning of an alternative document to receive printing comprising first and second document detecting means positioned on opposite sides of the printing path.
11. The improvement according to claim 10 wherein one of the document detecting means comprises a lever including the portion positioned for actuation by an alternative document upon insertion thereof into position to receive printing.