Legal Recognition

Wikipedia:

"Art. 74, 2 (h): In implementing the education policy, the state shall be charged with protecting and developing Portuguese sign language, as an expression of culture and an instrument for access to education and equal opportunities."

"Sign Language Legislation in the European Union", Wheatley, M., A. Pabsch., Edition II. Brussels, EUD, 2012:

"Portugal is one of the four countries in the EU mentioning sign language in its national constitution. Article 74 on education states:
2. In Implementing the education policy, the State shall be charged with: --;
h) Protecting and developing Portuguese Sign Language, as an expression of culture and an instrument for access to education and equal opportunities;

Unlike the constitutions of Austria and Finland, which mention sign language in the language section, the Portuguese Constitution refers to sign language in its article on education. It does not, however, specifically recognise Portuguese Sign Language (LGP) as a language in its own right, as can be seen with Austrian Sign language.
(..)
Portugal has a number of pieces of legislation that mention sign language apart from its constitution."