Forgery is false writing of a document of legal significance (or apparent legal significance!) with intent to defraud. It includes the making up of a false document or the alteration of an existing one. The writing need not be done by hand but can be by any means—typing, printing, and so forth. Documents commonly the subject of forgery are negotiable instruments (checks, money orders, and the like), deeds, receipts, contracts, and bills of lading. The forged instrument must itself be false, not merely contain a falsehood. If you fake your neighbor’s signature on one of his checks made out to cash, you have committed forgery. But if you sign a check of your own that is made out to cash, knowing that there is no money in your checking account, the instrument is not forged, though the act may be criminal if done with the intent to defraud.
The mere making of a forged instrument is unlawful. So is the “uttering” (or presentation) of such an instrument, whether or not the one uttering it actually forged it. The usual example of a false signature is by no means the only way to commit forgery. If done with intent to defraud, the backdating of a document, the modification of a corporate name, or the filling in of lines left blank on a form can all constitute forgery.