schema:             ROLE-SCHEMA
ref:                dn42.role
key:                role            required   single    schema
key:                nic-hdl         required   single    primary
key:                mnt-by          required   multiple  lookup=dn42.mntner
key:                org             optional   multiple  lookup=dn42.organisation
key:                admin-c         optional   multiple  lookup=dn42.person
key:                tech-c          optional   multiple  lookup=dn42.person
key:                abuse-c         optional   multiple  lookup=dn42.person
key:                abuse-mailbox   optional   multiple
key:                descr           optional   single
key:                remarks         optional   multiple
key:                source          required   single    lookup=dn42.registry
mnt-by:             DN42-MNT
source:             DN42