In legal writing, it is occasionally necessary to clarify the significance or meaning of a particular citation and how it relates to the writing. Introductory signals, also known as citation signals, are words and phrases used in legal writing to indicate to the reader how the writer intends to use a particular legal citation – whether it is for support, contradiction, comparison, or background information.

The use of introductory signals is notably complex and may frequently require judgment on the author’s part. As such, students and professionals experience some confusion with the subject. This guide will clearly explain the different types of introductory signals prescribed by the Bluebook in plain English and with examples.

An introductory signal can function in 4 different ways: support, contradiction, comparison, or background information. In this guide, we will take a look at contradiction, comparison, and background signals.

This is Part 2 of a 2-part series on Introductory Signals. See Part 1 here.



In your writing, there are instances when you want to reference a source or authority that directly contradicts the statement of judgment or opinion you are making. The introductory signal contra would be used in this case. It is helpful to think of contra as the exact opposite of the use of no signal—one signal is used to directly contradict your statement, and the other is used to directly support your statement.

Bluebook citation contra introductory signal

But see

Similar to the relationship between the introductory signals of no signal and contra, the use of but see is the exact opposite of see. Use the introductory signal but see in your writing when the authority or source you are referencing contradicts the statement of judgment or opinion you are making. In other words, but see is used when the reader has to make an inferential leap to establish that the referenced authority or source contradicts the statement in the writing.

Bluebook citation but see introductory signal

But cf.

The third type of contradicting introductory signal is but cf. This signal is the exact opposite of the introductory signal cf., Latin for “confer” (meaning “compare”) is used to indicate to the reader that while the statement being made in the writing isn’t directly supported by the citation, the citation still lends sufficient support (by analogy or otherwise). But cf. is used to indicate the same thing, only the opposite. But cf. indicates to the reader that while the cited authority or source doesn’t directly contradict the statement of judgment or opinion in the writing, it contradicts it by analogy.

Bluebook citation but cf introductory signal


Compare . . . with . . .

You may want to support a statement you are making in your legal writing by making a useful comparison between two authorities or sources. To do so, you would use the compare introductory signal. Compare must be used with the word with (see example below). The introductory signal, cf., is somewhat similar to compareCf. is used when you want to support the statement you are making in your writing by comparing the statement itself with an analogous source or authority. On the other hand, compare is used when you want to support the statement you are making in your writing by comparing two different sources or authorities. The writer will often include parenthetical information after the compare citation to explain its relevance.

Bluebook citation compare with introductory signal

Background Information

See generally

There are circumstances in legal writing where you would want to direct your reader to background information and material related to the statement you are making in your writing. In this case, the introductory signal see generally would be used. Often, the writer will include some parenthetical information after the see generally citation to explain the relevance of the background material or information being cited. A common error to avoid is using the introductory signal see also when see generally should actually be used. As a reminder, see also is used when a writer has already directly supported a statement they made in their writing with a citation but still wishes to add additional support.

Bluebook citation see generally introductory signal

Ordering Signals

In addition to the numerous rules related to how and when to use a particular introductory signal, the Bluebook prescribes specific rules about the order in which the signals should appear when more than one signal is being used. Refer to the table below for the correct order in which signals should appear.

Bluebook citation introductory signal chart with columns for signal, signal type, parenthetical explanation, and signal order position


This guide is a broad overview and reference to keep handy and look at over time. The rules from the Bluebook regarding the proper use of introductory signals are complex and require a fair amount of judgment. Use these Bluebook introductory signal examples and explanations as a starting point or a refresher. When creating your citation footnotes in your legal writing, be sure that your Bluebook citations are correct and complete. The LegalEase Citations Bluebook Citation Generator is designed to make the process as simple as possible while producing completely accurate citations. Try a free trial at LegalEase Citations today. Better citations lead to better grades. Better grades lead to law school success!

This is Part 2 of a 2-part series on Introductory Signals. See Part 1 here.