In many cultures there is a ban on mentioning the name of the deceased person

ban on mentioning the name of the deceased person shall be imposed out of fear to call it a spirit or ghost. Instead, the original name used some neutral response or assign a different name, such as the African Masai tribe. South American Indians who called guajiros dead man by the name itself could suffer a fatal punishment. In some tribes, Australian Aborigines, this taboo is so strong that even living namesake of the deceased forced to change names. Out of respect for the customs of Aboriginal people in the beginning of many Australian films and television meets the warning that the viewer can see the image or hear the voices of the dead.

via factroom.ru