# Where can I read about DER certificate structure - fields and its registered values?

Where is an official documentation for ASN1 structure and values of x509 certs?

Using OpenSSL command like openssl asn1parse -in server.der -inform DER I can see how the cert is structured, but, for example, value OBJECT :sha256WithRSAEncryption is HEX 2A 86 48 86 F7 0D 01 01 0B, or countryName identifier is 55 04 06 - where are all this values documented?