Honorary citizenship is Berlin's highest honour. It is awarded by the Senate in consultation with the House of Representatives to people who have rendered outstanding services to the city. The House of Representatives, the members of the Senate, the district offices and the district assemblies of councillors are authorised to nominate candidates. The honourees receive a certificate describing their achievements, signed by the Governing Mayor and the President of the House of Representatives. They may have their portrait painted by an artist of their choice for the gallery of honorary citizens in the House of Representatives. If necessary, they receive financial support. The Senate invites the honorary citizens to important events as guests of honour. They also receive a free annual ticket for Berlin's public transport system (BVG) and the Official Gazette of Berlin. The gravesites of honorary citizens of Berlin are recognised as honorary graves of the state of Berlin without further examination and for an unlimited period of time.