DOI
A permanent digital identifier that points to a work no matter where it moves online.
A DOI — Digital Object Identifier — is a persistent alphanumeric string assigned to a document, dataset, or other object, resolvable as a URL through doi.org. It exists to solve link rot: web addresses change when publishers reorganise, but a DOI is a promise that the identifier will keep resolving to the current location.
Every DOI has the same two-part shape: a prefix beginning '10.' that identifies the registrant, then a slash and a suffix chosen by that registrant, as in 10.1038/nature12373. Style guides now expect the full resolvable form (https://doi.org/10.1038/nature12373) rather than the bare string, and APA, Chicago, and MLA all require it when one exists.
For quotation work the DOI matters because it stabilises verification. A quoted passage cited to a DOI can be re-checked by any reader years later; the same passage cited to a news URL may become unverifiable in eighteen months. Where no DOI exists, the equivalent practice is to cite a permanent archive snapshot and give the access date.
Common mistake: pasting a session-specific database URL instead of the DOI. Those links usually carry account tokens, expire quickly, and often fail for anyone outside the original institution.
“https://doi.org/10.1000/182”
Keep reading the glossary
A formal reference that lets a reader locate the source of a quote.
The list of works cited or consulted, printed at the end of a book, chapter, or article.
The date you actually read an online source, recorded because online sources change.
The original record of a quote — the book, letter, speech, or recording in which it first appeared.