Written by attorneys · grounded in primary & secondary sources — see below
A citation signal directing the reader to an authority containing a statement that is analogous to or contrasts with the proposition for which it is cited.
Sources & Authorities· 17 primary sources
Select any source to read its text and confirm it supports the definition.
Cases
Uniform Acts
How it applies
Common Examples
6
Treaty Power Challenge
Caleb Chang challenged a federal statute enacted under an executive agreement that authorized warrantless searches of his home. His brief argued that the agreement could not override Fifth Amendment protections. The brief then cited a contrasting authority with cf. to show that structural limits on federal power remain intact even when international agreements are involved.
Federal Agent Liability
Connor Clark sued federal narcotics agents for an unconstitutional search of his apartment. The complaint sought damages directly under the Constitution. Counsel used cf. to point to an earlier decision recognizing that federal agents acting under color of authority possess greater capacity for harm than private trespassers.
Bivens v. Six Unknown Named Agents of the Federal Bureau of Narcotics403 U.S. 388, 91 S.Ct. 1999, 29 L.Ed.2d 619 (1971)
Gun-Free School Zone
Cynthia Cortez was prosecuted under a federal statute banning firearms near schools. She moved to dismiss on the ground that Congress lacked authority under the Commerce Clause. The motion cited an analogous decision with cf. to illustrate that legislation must be tied to an enumerated power rather than rely on attenuated effects.
United States v. Lopez514 U.S. 549 (1995)
Family Living Arrangement
Carmen Choi faced eviction under a zoning ordinance that limited occupancy to nuclear families. She argued the rule intruded on protected choices about family structure. Her brief used cf. to reference a decision striking down similar restrictions that burdened extended family living arrangements.
Moore v. City of East Cleveland, Ohio431 U.S. 494, 503 (1977)
Landmark Designation
Cobalt Energy owned a historic terminal designated as a landmark. The company claimed the restrictions prevented reasonable economic use of the property. Its complaint cited a prior takings decision with cf. to show that investment-backed expectations must be weighed against the regulation's public purpose.
Penn Central Transportation Co. et al. v. New York City438 U.S. 104, 98 S.Ct. 2646, 57 L.Ed.2d 631 (1978)
State Common Law Claim
Canyon Construction sued in federal court for injuries sustained on a railroad right of way. The complaint relied on general federal common law. Opposing counsel cited an analogous decision with cf. to demonstrate that state law supplies the rule of decision absent a federal statute or constitutional command.
Erie Railroad Co. v. Tompkins304 U.S. 64, 78–80 (1938)
Common questions
Frequently Asked
3
When should a writer use cf. instead of see or see also?+
Cf. is the weakest support signal. It is appropriate when the cited authority says something different from the proposition but is still analogous to it. Stronger signals such as see are used when the source directly supports the point.
Supporting sources
Does cf. belong in the support category or the comparison category of signals?+
Cf. falls under the support category even though the word literally means compare. It signals that the authority is analogous and provides indirect support rather than a direct statement of the proposition.
Supporting sources
Must the period after cf. be underlined in a citation?+
Yes. The abbreviation cf. is always followed by a period, and that period is underlined along with the signal when underlining is used for citation signals.
Supporting sources
304 U.S. 64, 78–80 (1938)Conflict of Laws
…whatever jurisdiction private right comes to be examined." See also Bank of Hamilton v. Dudley's Lessee , 2 Pet. 492, 525. Compare Jackson v. Chew , 12 Wheat. 153, 162, 168; Livingston v. Moore , 7 Pet. 469, 542. [^maj-3]: Pepper, The Border Land of Federal and State Decisions (1889) 57; Gray, The Nature and Sources…