This object specifies the backward signal requesting the receiving end send subscriber category information and then transition from Group C signaling back to Group B. This combines a data request, category, with a group transition in a single signal, meaning its correct configuration affects two things simultaneously, whether category info gets exchanged at all, and whether the call-state machine advances to Group B afterward. After Group C signaling has conveyed some detailed call information, this signal would both request the caller's category and move the exchange back into Group B for the remainder of the call setup.