What is the name of Wikipedia's policy that requires all content to be verifiable?

Wikipedia’s policy requiring content to be verifiable is called Verifiability. It means readers should be able to check significant claims against published, reliable sources rather than simply trusting an editor’s knowledge or assertion.

The policy is closely connected to Wikipedia’s sourcing rules. Editors are expected to provide inline citations for material that is challenged or likely to be challenged, as well as for quotations. The policy does not require every ordinary sentence to carry a citation, but claims that may be questioned should be supported clearly.

Verifiability is often confused with Neutral point of view and No original research. Neutral point of view concerns how competing significant viewpoints are represented; No original research prohibits editors from creating or publishing their own unpublished analysis. Verifiability is about whether information can be checked in an appropriate reliable source. A statement may be true yet still be unsuitable for Wikipedia if no acceptable source can be found.