The Biden administration is ordering U.S. immigration enforcement agencies to change how they talk about immigrants. The terms “illegal alien” and “assimilation” are out — replaced by “undocumented noncitizen” and “integration.” The new guidance is laid out in a pair of detailed memos sent Monday by the heads of U.S. Immigration and Customs Enforcement and Customs and Border Protection, part of a broader effort by the Biden administration to roll back the previous administration’s hardline policies and build what they call a more “humane” immigration system.