In, OES 2018SP3, DSfW supports schema level and features equivalent to AD 2019. After the domain upgrade, the schema level gets updated to AD 2019 level. This section describes the process to upgrade the domain and schema to AD2019 level.
Section 11.1, Updating the Domain Functional Level and Forest Functional Level
Section 11.2, Validating the Schema Update
Section 11.3, Validating Domain and Forest Functional Level