The decades-old White House press pool was created as a practical compromise between the news media and the nation’s chief executive: Instead of having a mob of journalists jostling to cover the president at every semi-public function, a handful of reporters are designated to act as proxies, or “poolers,” for the entire press corps. Poolers are chosen on a rotating basis from among regular White House correspondents, and they typically get more favorable access to presidential events to provide coverage that is shared with other reporters.

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While the overwhelming majority of pool reports pass through the White House without delay or amendment, some have been flagged by the administration’s press staff, which has demanded changes as a condition of distributing them.

via Reporters say White House sometimes demands changes to press-pool reports – The Washington Post.