Srila Bhaktivinode Thakura:

“A swanlike person can identify another swanlike brother who posseses all the appropriate symptoms, whether he is from the same country or not. Although their dress, language, worship, Diety, and behavior may appear different, they should freely address each other as brother. These type of people are called paramahamsas and Srimad-Bhagavatam is the scripture that is meant for such paramahamsas.”