Gestuno is an early version of International Sign often used at meetings involving many internationals. You’ll see it at events like Deaflympics and meetings of the World Federation of the Deaf. It’s a standardised international sign system. The book Gestuno: International Sign Language of the Deaf, published in 1975, has a list of 1500 signs. More grammar was informally added by interpreters and users over time. The choice of the word Gestuno is a reference gesture and oneness (Gest for gesture and uno for one).