answer:It varies by community. My sister’s husband was a deaf missionary in Ghana for a couple years. When he was there, he pretty much was the one that standardized the signs between the various communities. Each village had it’s own unique sign language and he took bits from each to create a language that could be understood by all. It helped that he was only there to set up the mission, and would be leaving. He was trusted to mediate so that no group felt slighted. Edit – I should add that he found the ASL signs used in Omaha, were different from those used in St. Louis, Rochester, or southern Wisconsin. So even in the US the signs are not always quite the same.