Where can i get the document and programs for learning G4NDL data structure?

I want to transfer ENDF-6 formatted data to G4NDL(Generalized Nuclear Data),
but it seems related information are too little,
so where can i get the document and programs for learning G4NDL data structure?

I am preparing a documentation explaining this format, I hope by September it will be ready.
But you may contact emilio.mendoza@ciemat.es, he is the one that makes the ENDF->Geant4 traslation

i look forward for your document,
i have emailed to emilio.mendoza a few days ago, but no reply.