IPv6 address encoding in commonName

[Robert Moskowitz]

I am fiddling around with an intermediate CA signing cert that the CA's 
'name' is it HIP (RFC 7401) HIT which is a valid IPv6 address. Actually 
a Hierarchical HIT as in draft-moskowitz-hierarchical-hip (to be revised 
soon).

For a client cert, it would be easy to put the HIT in subjectAltName per 
RFC 8002 (with a null subjectName), but a CA cert MUST have a non-empty 
subjectName.

Thus all I want in this subjectName is commonName with the HIT.

I am looking for examples of IPv6 addresses in commonName.

My searches today have come up empty.

Thank for any reference(s).