1997: Portugal, Legal Recognition of Portuguese Sign Language
Portuguese Sign language (Portuguese: Língua gestual portuguesa) is a sign language used mainly by deaf people in Portugal.
It is recognized in the present Constitution of Portugal. It was significantly influenced by Swedish Sign Language, through a Swedish school for the Deaf that was established in Lisbon."
Source: https://en.wikipedia.org/wiki/Portuguese_Sign_Language.
"The revised Constitution was published 20 September 1997, with PSL included in Article 74, Education:
In the implementation of its policy for education, it is the duty of the State:
- To protect and value the Portuguese Sign Language as cultural expression and instrument of access to education and equality of opportunities."
Source: https://core.ac.uk/download/pdf/62692087.pdf
Source: http://wfdeaf.org/news/the-legal-recognition-of-national-sign-languages/