In the Wiki, in the Resource Server section of the OAuth 2.0 Migration Guide there is a duplicate section:

==== Simplified Enablement

Spring Security OAuth's Resource Server support is enabled by https://docs.spring.io/spring-security-oauth2-boot/docs/current/reference/html5/#oauth2-boot-resource-server-minimal[adding the @EnableResourceServer annotation].

Spring Security's Resource Server support is enabled via the Spring Security DSL.