What is the domicile requirement for an immigrant visa?

What is the domicile requirement for an immigrant visa?

To qualify as a sponsor for an immigrant visa, a petitioner must be domiciled in any of the States of the United States, the District of Columbia, or any territory or possession of the United States. (A lawful permanent resident (LPR) sponsor must also maintain his or her LPR status.) But what exactly is the “domicile requirement”—and how do you correctly fulfill it?