Legal Citations and NexisUni: Shepardizing and Signals

"Shepardizing" refers to a standard set of extended signaling how different cases, rulings, and opinions have been cited. This is a quick way to tell whether a case (or part of a case) is followed (or disagreed with) in subsequent rulings. Perhaps most obviously, cases acan have a "positive" or a "negative" afterlife, in that some cases make stronger precedent than others, but there are many ways for cases to be cited that are considered "neutral" or not obviously negative or positive.

Shepard's is a venerable system that now finds its way into the basic structure of Nexis Uni, and even has conveniently visible color- and shape-based codes depending on how a case is treated by subsequent legal thinkers.  For reference, here's a full breakdown of the signals you may encounter.

Signal	Meaning
Red Stop Sign	Warning - Negative treatment indicated - indicates that citing references in the Shepard's Citations Service contain strong negative history or treatment of your case (e.g., overruled by or reversed).
Red Exclamation Mark in a White Circle	Warning - indicates that citing references for a statute in the Shepard's Citations Service contain strong negative treatment of the section (e.g., the section may have been found to be unconstitutional or void).
White Q in an Orange Square	Questioned: Validity questioned by citing reference - indicates that the citing references in the Shepard's Citations Service contain treatment that questions the continuing validity or precedential value of your case because of intervening circumstances, including judicial or legislative overruling as mentioned in the citing reference.
Yellow Triangle	Caution: Possible negative treatment indicated - indicates that citing references in the Shepard's Citations Service contain history or treatment that may have a significant negative impact on your case (e.g., limited or criticized by).
White Plus Sign in a Green Diamond	Positive treatment indicated - indicates that citing references in the Shepard's Citations Service contain history or treatment that has a positive impact on your case (e.g., affirmed or followed by).
White A in a Blue Circle	Citing references with analysis available - indicates that citing references in the Shepard's Citations Service contain treatment of your case that is neither positive nor negative (e.g., explained).
White I in a Blue Circle	Citation information available - indicates that citing references are available in the Shepard's Citations Service for your case, but the references do not have history or treatment analysis (e.g., the references are law review citations).

According to the Indigo Book, there are 4 basic categories of legal citation:

citations for SUPPORT;

citations for CONTRADICTION;

citations for COMPARISON;

citations for GENERAL REFERENCE or EXPLANATION.

Here's a breakdown of words used to indicate these relationships in the text of a legal opinion. (See https://law.resource.org/pub/us/code/blue/IndigoBook.html#R3):