I discovered on a ramp check in the PRC that all the mainland licences are held on a central CAAC database and this is what the ramp inspectors will check first. Yet, they didn't like our digital manuals. I suspect licence forgery has been an issue in the PRC as well. I have a mate who develops block-chain systems. I mentioned a block-chain system would be ideal for internationally recognised qualifications such as aviation licences. It would help prevent fraud.