What do you mean by "map"?

This is the IAC way of restricting the connection to these specific apps. Check https://wiki.mozilla.org/WebAPI/Inter_App_Communication_Alt_proposal#Publisher

The FTU and Settings will need to add the counter part of the rules system to request the connection *only* with the System app. Like in https://wiki.mozilla.org/WebAPI/Inter_App_Communication_Alt_proposal#Subscriber But that's part of other bugs.