Casetext's "SmartCite" Citator uses cutting-edge natural language processing and extensive human review to classify the appellate history of cases. As described below, SmartCite uses red and green  flags to to let you know how your case has been treated on appeal.  

A red flag indicates a case that is no longer good law because it has been reversed, overruled, vacated, withdrawn or superseded in whole or in part. When you see a red flag, you can click on that flag to get a link to the case that negatively treated your case on appeal.

As shown in the example below, Sturgeon v. Frost, 872 F.3d 927 (9th Cir. 2017) is no longer good law because the red flag indicates that it was reversed by Sturgeon v. Frost, No. 17-949 (U.S. Mar. 26, 2019):

A green flag indicates that a case was affirmed by an appellate court. When you see a green flag, you can click on it to get a link to the case that affirmed your case on appeal. 

As shown in the example below, Axis, S.p.A. v. Micafil, Inc., 681 F. Supp. 1271 (N.D. Ohio 1987) received a green flag because it was affirmed on appeal by the Sixth Circuit:

In general, the absence of a red or green flag means that the case was checked by SmartCite, and no negative or positive appellate history was found. That case is considered to be good law, even if it does not have a green flag indicating that it was affirmed on appeal. However, SmartCite does not cover opinions from administrative courts, such as the Board of Immigration Appeals. Cases that are not covered by SmartCite contain text below the title stating, "This case is not covered by Casetext's citator." 

While Casetext makes every effort to ensure that its SmartCite flags are accurate, please note that no case citator is perfect. SmartCite is intended to help attorneys determine how a case has been treated on appeal, but it is not intended to replace an attorney's review or judgment.

For more information on SmartCite, please see "How do I know if a case is good law?" and "Can I see how one case has been cited by other cases?"