CIK

The Central Index Key, or CIK, is the number EDGAR assigns to each filer. The SEC's EDGAR documentation says EDGAR "assigns to filers a unique numerical identifier, known as a Central Index Key (CIK), when they sign up to make filings to the SEC," and that CIK numbers "remain unique to the filer; they are not recycled." The CIK lookup page adds that it is used "to identify corporations and individual people who have filed disclosure with the SEC." CFO Tribune groups each company's records by its CIK, so a company that changes its name stays one company on the record, and each company page links its CIK to the company's EDGAR filings.