When is the entire function group added to the transport request

When you modify a functionmodule in a function group, only the object of the functionmodule( LIMU FUNC) is added to the transport request.

When you modify an include of the function group, the reportsource of that include (LIMU REPS) is added to the transport request.

But under some circumstances the entire function group is added to the transport request (R3TR FUGR).

Can somebody clarify under what circumstances the entire Function Group is added to the transport request?