To activate RBS:
(pause means the * key held in until box appears)
[pause] [pause] [pause] 1 1 3 [pause] 1 [pause] [ok]
You now have to press the [MENU] and scroll to the 'Eng Field Options' function with the keys, and enable it.
To de-activate RBS,
[pause] [pause] [pause] 1 1 3 [pause] 0 [pause] [ok]
This only works with some versions of software. Please report what works and doesn't for you.
Reported working, by country:
d460: IT
6200 Flare:
UK (Orange), AU
7500: IT
(model: F16 HW: 5.2 SW: 2.1)
8200: ES,
AU, NL, BE
8400: IT,
NL
8700: AU,
IT, SG, DE, ES, ZA