Flemish to English Other Certificates, Diplomas, Licenses, CVs birth certificate

Can anyone please tell me what is exactly meant by this? I can't put "unsealed paper" really... It comes at the bottom of quite a lot of birth certificates and I am wondering if it is a different way of saying "vrij van zegel" - i.e. presumably that no stamp duty is payable because the certificate is for "sociale doeleinden". Many thanks for any insight