minimum viable CSR?

[Felipe Gasper]

Hello,

        I have domains whose length exceeds the commonName maximum. To create a 
signing request for such a domain, then, I can’t put the domain in the CSR’s 
subject.

        Assuming that I’m interested in just a DV certificate--such that the 
CSR’s subject DN actually provides no useful information--what would the 
minimum-viable subject look like from the generation-via-OpenSSL side?

        Thank you!

cheers,
-Felipe Gasper