If you have ever read a Supreme Court opinion in its original form as released by the Supreme Court, you may have noticed this statement at the top of the first page:
NOTE: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued. The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader. See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.
The law nerds among you may be wondering, what is the point of that citation?
Here's the scoop. United States v. Detroit Timber & Lumber Co., 200 U. S. 321 (1906), was a property dispute. Counsel for one of the parties relied in its argument on a precedent, Hawley v. Diller, 178 U.S. 476 (1900), as authority. But instead of relying on the Hawley case itself, counsel relied on the more favorable description of the case found in the Reporter's summary of the case. The Court in Detroit Timber & Lumber Co . admonished counsel for relying on the Reporter's summary:
[T]he headnote is not the work of the court, nor does it state its decision — though a different rule, it is true, is prescribed by statute in some States. It is simply the work of the reporter, gives his understanding of the decision, and is prepared for the convenience of the profession in the examination of the reports. . . . And finally the headnote is a misinterpretation of the scope of the decision.
So the citation to Detriot Timber & Lumber Co. provides case support for the idea that the Reporter's summary is not part of the Court's opinion and is only the Reporter's summary for the reader's convenience. A lawyer over a hundred years ago made the mistake of relying on the summary: Don't follow him.
Incidentally, the Court's criticism of the Reporter's work as "a misinterpretation of the scope of the decision" may have been easier to make given that the Reporter of Decisions at the time of Hawley had retired in 1902, two years after Hawley and four years before Detroit Timber & Lumber.