I'm the author of Salt Windows package manager. Those install_flags refer to the silent install options that your application installer provides. Sometimes passing a /? or /h to the installer at the command line will tell you what options are available.
Also, the wpkg project has a fantastic wiki documenting many of the silent installer switches here: http://wpkg.org/Category:Silent_Installers
A quick Google search revealed this doc as well: http://documentation.softwareag.com/webmethods/wmsuites/wmsuite8_ga/System_Management_Hub/install/tomcat_windows_install.htm#d0e2149