The bulk of most patent documents is dedicated to the specification, which consists of a description and the claims. Below are some of the most common sections of the description (note that description section titles may vary from patent to patent, and description sections are only included as necessary, e.g., a patent with no drawings would not include a Description of Drawings section).
Cross Reference to Related Applications
In the oat plant patent example, this section refers to the provisional patent application filed in April 2013 for the same invention.
Background of the Invention
This section typically refers to an existing need or market for the invention and sometimes refers to prior art.
This section describes the invention in brief.
Description of Drawings
This section explains each drawing in the Drawing Sheets section. In the oat plant example, this is titled Brief Description of the Figures, and provides only an overview of each drawing. Details about the drawings are integrated into the Detailed Description section.
The detailed description includes all information about the structure of the device and how it functions. In the oat plant example, this description focuses on details illustrated on the drawing sheets, including the pedigree of the variety, how to create new oat varieties using the variety claimed in the patent, and the traits that make the variety desirable. The applicant has titled this section Detailed Description of the Invention.
Glossary of terms used elsewhere in the patent document.
In the case of biological materials, including seeds and tissue cultures used to propagate asexually reproducing plants, the USPTO may determine that a physical deposit is required to sufficiently enable the public to make or use the claimed invention. To satisfy this requirement, the applicant will deposit a sample (or multiple samples, if the patent claims cannot be enabled with one unique deposit) with a recognized International Depository Authority and indicate the accession number(s) under which the deposit(s) are located. After the patent is issued, these accessions are, in most circumstances, available to the public upon request, provided that the requestor obtains a certificate from the USPTO affirming that they are authorized to receive samples of the deposit.