Is it true what some people in Algeria do regarding wailing 40 days after a person's death, offering Sadaqat (charity), and reciting the Qur'an and Dhikr (remembrance of God) for them on this occasion?

The fortieth-day commemoration of the deceased is an innovation. Giving charity on behalf of the deceased and reciting the Qur’an for them are, most likely, permissible. However, gathering for the fortieth day and wailing are prohibited by Islamic law.