A partially known environment is a type of penetration test where the tester has some information about the target, such as the IP address, the operating system, or the device type. This can help the tester focus on specific vulnerabilities and reduce the scope of the test. A partially known environment is also called a gray box test1. References: CompTIA Security+ Certification Kit: Exam SY0-701, 7th Edition, Chapter 10, page 543.