What is the meaning of complementary close?

== == Complimentary close, or Complimentary closing is the term, expression, or phrase which immediately precede the signature on a note, letter, or correspondence, most often written. The Word or Words so written express the esteem or regard for the person to whom the correspondence is directed. It is sometimes confused with valediction, which is the act of bidding farewell, especially orally. English language complimentary closings typically contain the Word yours, a contraction of your servant; old closings were usually some voluminous statement, a complete sentence of the form. * Customary expressions used to close a formal business letter include Thank you, Sincerely, Sincerely yours, and Yours truly. Less formal expressions such as Regards, Best regards, and Best wishesshould be used only when the writer is addressing a business associate that is also a friend. * When the expression contains two Words, such as Thank you, only the first Word receives an initial upper case letter * A comma follows all forms of a complimentary close.