https://tomcat.apache.org/tomcat-10.1-doc/api/org/apache/catalina/valves/AbstractAccessLogValve.UserElement.html
AbstractAccessLogValve.UserElement (Apache Tomcat 10.1.55 API Documentation)
declaration: package: org.apache.catalina.valves, class: AbstractAccessLogValve, class: UserElement
apache tomcatapidocumentation