In the following years, a pidgin developed as the delegates from different language backgrounds communicated with each other, and in 1973, a WFD committee ("the Commission of Unification of Signs") published a standardized vocabulary. They selected "naturally spontaneous and easy signs in common use by deaf people of different countries"[9] to make the language easy to learn. A book published by the commission in the early 1970s, Gestuno: International Sign Language of the Deaf, contains a vocabulary list of about 1500 signs.