APPROVED SOCIETIES. In pursuance of its policy of grouping the compulsorily insured population in voluntary insti tutions, the National Insurance Act of Great Britain, which became law in 1911, provides that any respectable thrift institu tion, or body of persons, may adapt itself or establish itself to carry out the work of health insurance. Under rule, such a body may be approved by the Ministry of Health and thus become an "approved society." The main conditions of approval are (I) that the society must not be carried on for monetary profit and (2) that it must be subject to the absolute control of its mem bers. Insured persons may choose to join any such approved society, but an approved society is given the right to reject any insured person applying for membership. Generally, the British friendly societies have become approved societies under the Act, and many trade unions and collecting societies have formed separate sections to avail themselves of the special provision en abling them to constitute such sections as approved societies (see NATIONAL INSURANCE : HEALTH).