To represent the Mirandese language, it's used the flag of the municipality of Miranda do Douro, sometimes used to represent the whole council:
A flag consisting in a banner of arms of the previous coat of arms could be misunderstood as a flag only centered on Miranda do Douro council, although the idea could be reused.
My proposal is the following:
I moved the Miranda do Douro arms to first canton (the position of honor), for being synonym to Mirandese language. The other three quarters represent the other regions where Mirandese is spoken, that are widely three: the two parishes of Vimioso and the village of Mogadouro. The blue cross fimbriated in white represents the first flag of Portugal, for the fact that the Mirandese is identified with Portugal.
Comments are very welcome! Feel free to comment.
Click here to access an interesting site about the Mirandese language.