“All new functionality in the SQL standard is in the form of optional features, so I’m giving the feature codes and names below for reference.”
SQL:2023 finally lets you write VARCHAR without a length, adds GREATEST and LEAST, and gets a native JSON type because time ran out in 2016. The old text was ambiguous about whether nulls are distinct in a unique constraint. The fix makes the default implementation-defined. Every new feature is optional, so the standard mostly writes down what many databases already ship.