Avoid Saying Too Much

In the background, as in other sections of the patent application, it is all too easy to say too much. Perhaps the most common mistake in that regard is to discuss the invention being claimed in the application. Don't do that. Keep the background directed to the prior art. The first hint of the claimed invention should come at the very end of the background section, where the applicant states what problems still remain in the field.

Another blunder is to refer to prior uses, patents, and other disclosures as prior art. The term "prior art" may indeed be appropriate. But it is a term of art in patent law, and use of that term is effectively an admission that the references are relevant to patentability of the presently claimed inventions. There is no need to go down that road. The references are either prior art or they are not. In either instance there is no advantage to admitting that they are prior art.