It is not customary, and considered impolite, for aboriginal people to ask someone his/her name directly or to say one's own name. Thus, the European custom of prefacing every transaction with 'Name and date of birth?' is incompatible with aboriginal practice. Kinship customs may affect prisoners in various ways: avoidance relationships are observed between certain kin; obligation relationships may cause problems if an aboriginal person is placed in a position of authority over other Aborigines; and significant relationships are not always defined in the same way as for Europeans. For many Aborigines, English remains only a second language in which skills range from rudimentary to fluent. Time concepts are notoriously different; tribal Aborigines seldom refer to clocks or calendars. Tribal communities often recognize as valid only their own system of crime and punishment. Mabarn or 'witchdoctors' are the closest equivalent to psychologists in aboriginal culture. Their methods exclude the close interrogation of their clients about their sexual practices. Three practical measures can be taken by all prison departments: employment of aboriginal staff, particularly as welfare officers, and in other support service roles; adequate training of prison staff at all levels in relevant aspects of aboriginal culture; and employment of anthropologists who have studied aboriginal cultures in some depth.