You might have encountered the below shown post circulating on Facebook, the post tells that your cellphone has a secret "name" and any user can discover it by typing the last three digits of your phone number into the comments section. Apparently, it works and a name gets displayed when this is done from your mobile phone. However, the reason is not that your phone has a secret identity but because the bracketed code is a short-code which corresponds not to your phone but to a real Facebook user identity who's name gets displayed when you use it.