What is a (35 USC §123(a)) or a (15 CFR 123(a))?
USC means United States Code; CFR means Code of Federal Regulations
These citations* are shorthand for the laws and regulations that explain in precise terms what is needed in order for the Federal government to do business. Each is a citation which refers to a particular section of the law or its implementing regulations.
Each law is signed by the President after being enacted by votes of the House of Representatives and Senate. Many new laws are assigned a number in the United States Code which reflects their relationship to similar laws or laws that govern similar programs. The way laws are created follow a formal process which you can learn more about from "How Our Laws are Made."
The Code of Federal Regulations is written to explain in detail how the laws are to be carried out. When a law is written, it usually does not explain in great detail what procedures are to be followed, nor does it include descriptions of the special situations which can arise. This is the job of the regulations, which govern the day-to-day business of the Federal government.
Regulations are written by the government agencies responsible for the subject matter of the laws. The United States Patent and Trademark Office writes the regulations concerning patents and trademarks which are found in Title 37 of the CFR.
Below are diagrams explaining how to read these notations:
Citations of United States Code
35 USC §123(a)
Citations of Code of Federal Regulations
15 CFR §123(a)
15 = Title 15, Federal Regulations are divided into various Titles
CFR = Code of Federal Regulations "how to implement the law"
§ = a symbol meaning "section"
123 = The section number within this particular Title
(a) = a paragraph within a section, labelled "(a)"