What is the current state of the law on the definition of a writing?

Defendant now contends the court erred when it expanded the definition of a writing. At trial, however, the court and counsel conferred at length about how to respond to the jury's question. When the court asked defense counsel if there was an objection to the proposed response, counsel stated: "I think the court's the proposed portion of the answer with regard to how a forgery can be expressed, as you put it, is accurate, that it can be an electronic form, electronic format." Counsel went on to request the jury also be given a definition of forgery. Defense counsel agreed the court's response to the jury was correct. Defendant did not raise this issue during trial, but simply wanted another definition to be included in the response. Accordingly, defendant's argument on this point is forfeited. (People v. Roldan (2005) 35 Cal.4th 646, 729.)