What is a covert message in Facebook
I do not assume it in fact exists : http://www.google.com/search?hl=en&q=facebook+cloaked+message
Your colleague MAY be speaking about a Firefox plugin called CloakGuard. It calls for all customers to have actually the plugin mounted and also permits you to obfuscate particular sections of your web content on Gmail, Facebook, and also a couple of others making use of a password.
Not exactly sure just how well it functions and also have not directly attempted it. Below's a few videos showing it in action.