The `java.security` security properties file and those referred to by the `java.security.properties` system property now support including other properties files. The directive `include <path-to-a-file>` can be used for this purpose. The effect of including a file is equivalent to defining its properties inline at the inclusion point. See more information and examples in the Security Properties Files Inclusion section of the Security Developer Guide and in JDK-8319333.

As a result of this change, the name `include` can no longer be used to define a property in a security properties file. If the name `include` is passed to the `java.security.Security::getProperty` or `::setProperty` APIs, an `IllegalArgumentException` is thrown.