https://access.redhat.com/documentation/en/red-hat-jboss-enterprise-application-platform/7.0/development-guide/chapter-13-hibernate#hibernate_validator

The section 13.6.2. Hibernate Validator pretty much only repeats what has been already said in 13.6.1. About Bean Validation. I think this is unnecessary duplication of information, so I suggest to remove this short section because it doesn't add anything useful.

In addition to this, for the same reason, I also suggest to remove this sentence

For more information, refer to Hibernate Validator and About Bean Validation.

from the end of section 13.6.3.1. About Validation Constraints