For example, there could be a mysubsystem.properties file, containing the following:
Place holders are used for system-wide properties, such as dir.root in the -context.xml and .properties files, as the child application context will recursively expand place holders for its own properties and all the place holders recognized by its parent.
Properties files in the subsystem directory declare the configuration parameters and provide default values where these have not been supplied elsewhere. These files should not be edited in order to configure the subsystem.
See Modifying global properties for more information on how to configure a prepackaged subsystem.