Under your handwritten signature, your entire typewritten name and designation (on separate lines) should display. If you don't know the person's name, start your letter with Dear Sir or Dear Sir, or Madam or Dear Madam, and conclude with Yours Faithfully, followed by your complete name and designation. If you are writing to more than one recipient, indicate which one(s) you are addressing with a specific reference (i.e., Mr., Mrs., Ms., Dr., etc.). You can also use first names only if the recipients are close friends or relatives who would not object to such familiar communication. In most cases, a simple "Sincerely" will suffice as a sign-off. However, if you are sending correspondence that may contain personal information, it is advisable to add a disclaimer at the end of the letter to avoid any future misunderstandings or controversies arising from your use of this material. The following example shows how a simple "Dear John:" can be expanded upon by adding John's full name along with his job title and organization before signing off: "John Doe, Vice President - Sales & Marketing". This makes it clear that information about John was provided on purpose and not by accident. Signing off letters is a formal way of saying goodbye, and as such, various terms have evolved over time to include different nuances and levels of formality.