Some companies don't want customers or vendors to know the telephone numbers of their employees. For example, Ford may decide that calls from their Customer Support Center should show the 800-number for the Center and a name like "Ford Support," instead of the real direct-dial phone number of each support representative placing a call. Microsoft may want to give their employees the option of telling people their phone number, instead of having everyone they call be able to glance at their caller ID and know their extension. In this way the company is able to maintain the confidentiality of internal numbers.