26:18 · A protecting sign for invaluable ancient relic or culturally invaluable building or monument intended to protect against bombing etc. The ideogram is called Roerich sign after its creator. It was introduced after international conferences held during the 1930s. It has, however, seldom been used, as witness the enormous devastations of culturally invaluable buildings by bombing during World War II.
    The structure is the same as that of a sign worn by deaf persons to protect them in traffic.
    Compare with in Group 8 with a similar meaning.