Slip opinion
A court's decision as first issued, before official publication, and the version everyone actually reads.
A slip opinion is the decision as the court releases it on the day it is issued. It is complete and it is the operative ruling, but it is not yet the official published version, and courts note that it remains subject to formal revision before appearing in the bound reports. Typographical and citation corrections are ordinary; substantive changes are rare but not unknown.
It is the version that matters for coverage because it is the version that exists in time to report. Official publication can lag by a year or more. Practically, this means quoting a page number from a slip opinion is quoting something that may later be repaginated, so the reliable citation is to the case and the part of the opinion rather than to a page.
Slip opinions are works of the United States Government and carry no copyright, so they can be quoted at length, which is why coverage of a decision here can rest on the court's own words rather than on a characterisation of them. Each is filed on the case docket alongside the briefs, including any amicus filings.
What the federal government did, once a day.
One email each weekday: the rules, filings, votes and Fed decisions that actually changed something, each one linked to the document it came from.