Actually, it is (kinda) here https://wiki.unraid.net/DockerTemplateSchema, but TBH it's not recommended to follow it (ie: I consider the xml specification to be an internal data structure). You're best off not worrying about creating the xml itself. Let dockerMan do it for you. Docker - Add Container, and fill out everything, then either apply (container will install and xml will get saved in /config/plugins/dockerMan/templates-user or hit SAVE and copy the entire xml that appears. See also https://forums.unraid.net/topic/57181-docker-faq/?tab=comments#comment-566084