Salam
What is the true Islamic practice of naming children? Should they have common surnames, known by their mothers or fathers?
Regards.
Salamun Alaikum,
The Quran is clear that children should be known by their true parentage and known by their fathers (abaihim 33:5). If the fathers are unknown, then they are brothers in religion and your 'mawali' (friends, clients, kinsfolk, inheritors etc) (33:5).
I hope this helps, God willing,
Regards,
Joseph.