The standardised form of PNGSL was made an official language of Papua New Guinea in 2015.
However, tests so far have found that speakers from different areas of PNG have been able to communicate with each other, though there is great regional variation due to the influence of home sign.
[1] Auslan (Australian Sign Language) was introduced to Papua New Guinea in the 1990s.
[2] There was influence from Tok Pisin and more importantly mixture with local or home sign, as the languages diverged to the point where, by 2015, it was estimated that they were only about 50% mutually intelligible and that native speakers of Auslan and PNGSL were not able to understand one another.
[1][needs update] Separate, local sign languages have been described in Enga[4] and Chimbu provinces.