Another aspect of fraudulent behavior is it's similarity to white-collar crime. In many ways, forgery and fraud offenses are the hybrid of all hybrid crimes. Although most crimes against business are distinguished by the means used to carry them out, forgery is a specific intent crime while fraud is a general intent crime. Forgery requires a rather unusual mental state which easily distinguishes it from other crimes of theft. With fraud, it's sometimes said that it must always be intentional, as distinguished from negligent, but there are so many different forms of fraud, spelling out so many different circumstances, that it's probably better to refer to fraud as requiring constructive intent.
Forgery is limited to documents.
There can be no such thing as a forgery of art or forgery of machine because these items are not written documents. The person must have taken a genuine document and changed it in some significant way. It's the writing itself which must be false, not the document. This element is intended to cover situations involving false signatures or improperly filling in blanks on a form. The document or writing has to at least look genuine enough to fool people.