Interventions on monuments shall be performed only by specialists, experts and certified technical experts. Their certification is based on skills assessment determined by: a) basic training, b) professional seniority, c) experience gained through direct participation in activities in the field of historical monuments under the guidance and signature certified specialists or experts. The specializations for which certifications are granted are: a) research and inventory of historical monuments, B) verification/technical verification, C) complex project leader, D) specialized project leader: architectural restoration, historic structures, installations engineering , artistic components and/or historical urbanism, E) execution of works, F) supervising of works, G) monitoring the behaviour in time of the historical monuments.