In my research, I found some RFCs that have not been updated in over a decade, e.g draft-ietf-pkix-ldap-crl-schema-01.
I also explored several public directories used in PKI (e.g.
x500.bund.de) and established that they chose not to stick to that RFC. Other directories I found did not follow that recommendation either.
At this point I am under the impression that people roll their own schema, as I failed to find some consensus in this regard.
What reading material do you recommend for determining a schema for PKI? And in the same context, if you happen to run such a server - what schema did you choose, and why?