schema:             TINC-KEY-SCHEMA
ref:                dn42.tinc-key
key:                tinc-key      required  single    primary schema
key:                tinc-host     required  single
key:                tinc-file     required  single
key:                descr         optional  single
key:                remarks       optional  multiple
key:                compression   optional  single
key:                subnet        optional  multiple
key:                tinc-address  optional  single
key:                port          optional  single
key:                admin-c       optional  multiple  lookup=dn42.person,dn42.role
key:                tech-c        optional  multiple  lookup=dn42.person,dn42.role
key:                mnt-by        required  multiple  lookup=dn42.mntner
key:                source        required  single    lookup=dn42.registry
mnt-by:             DN42-MNT
source:             DN42