The specification, which is also called the disclosure, is a written description of an invention. The patent specification is drafted both to satisfy the written requirements for patentability, as well as to define the scope of the claims. While the layout of a specification varies from place to place, it is relatively consistent between the U.S. and Europe, except that B and C are unique to the U.S. For the purposes of this tutorial, the claims are described separately from the specification.
The sections of a patent specification are:
A. Title of the invention. The title of the invention is designed to describe the essence of the invention in a few words.
B. Cross-reference to related applications. In the U.S., it is required that a patent applicant include a section titled "cross-reference to related applications". In this section, the applicant lists any provisional patent applications that they are claiming priority to, or if the application is a continuation, the parent application number(s).
C. Statement regarding federally sponsored research (if applicable). In the U.S., it is also required that the applicant include a "statement regarding federally sponsored research" if the invention was made under a government contract, or if federal grant money was used to fund the research.
D. Background of the invention. The background of the invention is typically drafted for a jury audience. Selected art in the field is discussed to emphasize differences with the current invention, and to point needed improvements that are provided by the current invention.
E. Summary of the invention. The summary of the invention, which is distinct from the abstract, is meant to discuss the invention (i.e., the claims) rather than the disclosure as a whole. Often, the summary will discuss advantages of the invention or how it solves the problems existing in the art, such as those presented in the background of the invention.
F. Description of the drawings. If drawings are included in the application, a brief description of each drawing is required.
G. Detailed description of the invention. The detailed description of the invention is the meatiest section of a patent. Its purpose is to adequately and accurately describe the invention. There are generally two sections:
- A general explanation of the invention and how to practice it. The invention is described in its broadest sense, to show that the inventors have a broad view of the scope of the elements. Often, preferred embodiments of the invention are described. Such embodiments are generally more limited versions of the broadest concept and are provided for support for a fall-back position of narrower claims if the broader concept is not patentable. Definitions of key terms are often provided and are extremely important in interpreting the scope of the claims.
- Specific examples of how to practice the invention. A patent application does not require examples, however in practice, examples can often assist in showing patentability (e.g., enablement). The examples may or may not have been performed by the inventors. "Working" examples present completed undertakings. "Prophetic" examples are hypothetical undertakings and are always written in the present or future tense. Typically, the examples demonstrate practice of one or more specific embodiments of the invention.
(Many new readers find the purposes of these two sections confounding and assume that the examples set forth how the invention will be practiced. Rather, examples are meant only to illustrate, but in no way to limit, the claimed invention).
H. Sequence listing. A sequence listing is required if the application includes nucleic acid or amino acid sequences. If sequences are disclosed, every nucleic acid molecule that is at least ten nucleotides, and every protein that is at least four amino acids, must be included. In many jurisdictions, sequence listings are required to be in a specific text format. The USPTO provides a free software download called PatentIn that is often used to compile sequence listings.
I. Abstract. The abstract is a brief summary of the entire specification.