For every scr path, there is one file in a scrconf directory. During startup, the scr does only read the first line, which contains the scr path.
When the scr path is used, the scr starts (called mount) the agent. This can be a builtin, plugin or external program. Example:
SCR(`Read(.etc.hosts));
You can also explicity mount a scr path:
SCR(`MountAgent(.etc.hosts));
The gimmick is, you can also unmount a scr path:
SCR(`UnmountAgent(.etc.hosts));
This destroys the agent, thus freeing it's memory. Plugins are unloaded and external programs stopped/killed.