This is an example USDA result from creating a reference with the CreateReference command.

#usda 1.0
(
    endTimeCode = 100
    metersPerUnit = 0.01
    startTimeCode = 0
    timeCodesPerSecond = 60
    upAxis = "Y"
)

def "World"
{
    def "ref_prim" (
        prepend references = @file:/C:/path/to/file.usd@</World/some/target>
    )
    {
    }
}