Passage: The children remained linguistically disconnected from their teachers, but the schoolyard, the street, and the school bus provided fertile ground for them to communicate with each other. By combining gestures and elements of their home-sign systems, a pidgin-like form and a creole-like language rapidly emerged. They were creating their own language. This "first-stage" pidgin has been called Lenguaje de Signos Nicaragüense (LSN) and is still used by many who attended the school at this time.Staff at the school, unaware of the development of this new language, saw the children's gesturing as mime and as a failure to acquire Spanish. Unable to understand what the children were saying to each other, they asked for outside help. In June 1986, the Nicaraguan Ministry of Education contacted Judy Kegl, an American Sign Language linguist from MIT. As Kegl and other researchers began to analyze the language, they noticed that the young children had taken the pidgin-like form of the older children to a higher level of complexity, with verb agreement and other conventions of grammar. This more complex sign language is now known as Idioma de Señas de Nicaragua (ISN).

Question: What does LSN stand for?
Lenguaje de Signos Nicaragüense