A patent citation refers to any important document or research paper cited by a patent applicant, patent examiner, or third party in relation to the content of a patent application. These citations can include various types of publicly available patent documents, such as existing patents, journal articles, research papers, publications on the internet, trade show disclosures, and conference abstracts1. There are two main types of patent citations:

1. Backward citations: These are patent documents (also known as “prior art”) that have been published and are publicly available before the filing date of the patent application. Patent examiners often add their own prior art to patent applications, helping to identify relevant background scientific literature and patents related to the underlying invention. Reviewing backward citations can provide insights into what the Patent Office considers the most relevant prior art for a given patent.

2. Forward citations: These are patent documents that have been recently published and have cited the underlying patent application. After a patent application is filed, it may be cited by journals, research papers, n