Spoiler

You may be looking for this wiki's spoiler policy or The Spoilers (comic story).

Spoilers were things one individual knew about another's personal future. River Song particularly favoured the term, and used it to warn the Tenth and Eleventh Doctors when they asked questions that she couldn't answer without revealing details about their futures. (TV: Silence in the Library, The Name of the Doctor)

The Tenth Doctor first heard the term from River when they met in The Library, but River first heard the term from the Eleventh Doctor in Hitler's Germany. (TV: Silence in the Library, Let's Kill Hitler)

Of course, neither the Doctor nor River was the originator of the term. Certainly the Doctor had heard and used it long before meeting River. While being tortured by Little Brother of Faction Paradox in San Francisco, the Eighth Doctor strongly cautioned him against revealing any spoilers. (PROSE: Unnatural History)

Other companions also knew the term. Fitz Kreiner once wrote a song called "Contains Spoilers" which he assured his audience did indeed contain spoilers. (PROSE: The Gallifrey Chronicles)

Behind the scenes

Steven Moffat included the reference as a slight dig at fans who wanted to know details of forthcoming episodes of Doctor Who before they aired. (CON: Shadow Play)