How is a forbidden national sign langauge revived?

For over 100 years, the deaf of New Zealand were not
permitted to use sign language. The deaf continued
to use sign language – underground – while hearing
people either looked the other way or knew nothing
about it.

The government, during the eighties, decided to
recognize the sign language. Permitted to use the
language in the open, the underground sign
language was “rusty” and not up to the times.

It took efforts of interpreters and teachers and
deaf leaders to “formalize” the permitted sign
language – through classes and through workshops
and through seminars.

It took quite some time, but finally the New Zealand
sign language became just as smooth as the other
sign languages – ASL, British Sign Language,
French Sign Language and so on!

Milan 1880? Not really – Gallaudet always advocated
ASL; same as with deaf clubs whereas many deaf schools
suppressed it.

And as a cruel irony, while the government approved
sign language, the governent would not provide