Knowing how to cite patents can be a useful skill if you need to write articles or other documents that include information about patented inventions. It can also increase your chances of getting a new patent application approved and provide valuable competitive and market insights. There are several different style guides for citing patents, ranging from the ACS Style Guide to the Chicago Manual of Style.

How to Cite Patents

If you need to cite a patent or patent application when you are writing a research paper or article, the format of the citation depends on the style manual you use. It is essential that you check with your editor, publisher, or instructor to determine the right format. Below are a few style manuals that are commonly used for citing patents:

ACS Style Guide

According to the ACS Style Guide, the minimum information needed for an acceptable patent citation includes:

  • Name of the patent owner
  • Patent number
  • Date

Also, make sure that the stage of the patent, which can be “patent” or “patent application,” is indicated and the pattern of the patent number, including spaces, dashes, and commas, is exactly the same as that of the official patent document. If possible, you should also include the title and chemical abstracts reference, which must be preceded by a semicolon. In the U.S., patent numbers must be written with commas. If the patent is granted in another country, it should be written in the same way as the original patent number.

Chicago Manual of Style

When you are using the Chicago Manual of Style, you have to cite a patent under the name of the inventor and date it according to the year of filing. The year of issue should be repeated to prevent ambiguity. If a patent citation has more than one date, it should include both the filing and issuance dates.

MLA Format

If you are citing a patent using the MLA format, you must include the following elements:

  • Name of the patent owner
  • Title or description of the patent
  • Patent number
  • Name of the agency that issued the patent
  • Date of issue

If the information about the patent is found online, you have to include the website's name and URL.

Power of Patent Citations

Due to the massive volume of patent citations and their complicatedness, navigating and exploring patent citation data can be a daunting task. However, in spite of these challenges, using citations for analysis and business intelligence offers many benefits.

A patent citation refers to a document that is cited by a patent applicant, patent office examiner, or third party because its content is relevant to a patent application. Any document that is publicly available can be cited, including:

  • Existing patent publication
  • Internet publication
  • Journal article
  • Conference abstract
  • Oral disclosure

Two Types of Patent Citations

Backward Citations

A backward citation is a document that was published earlier and became publicly available before the date of submission of a new patent application. It is also known as “prior art.” This type of citation is useful for finding patents and literature that are closely related and supplementing or enhancing an initial classification or keyword-based search.

A backward citation that is identified by a patent examiner is also categorized based on its relevance to the patent application. The classification can be used to quickly narrow down a patent search to the most appropriate prior art. It is common for different patent examiners to cite different prior art against a particular invention, so it is a good idea to review the backward citations of every patent family member.

Forward Citations

A forward citation is a document that was published more recently and has been used to cite a new patent application. From a business or competitive intelligence perspective, this form of citation is useful for identifying players in a field that is similar to that of the new patent application. For instance, monitoring forward citations enables one to identify new competitors in a similar field, potential infringers, and licensing opportunities.

When analyzing forward citations, you should take note of the time lag effect, which means that patents that are more recently published have fewer forward citations than older ones. This is especially important when comparing patents based entirely on the number of forward citations.

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