You should note additional documents in the ending notations of a letter. A resume, invoice or price list are examples of documents that are sometimes enclosed in the same envelope with a letter. If you are sending a copy of the letter and enclosures to someone other than who it is addressed to, this is noted by CC, which stands for copy to, in the ending notations as well.
Type on the left-justified margin "Enc:," "Encl:" or "enclosure:" directly below the reference initial line.
State what type of enclosure is included in the envelope. For example, "Enclosure: invoice" indicates that an invoice is also included in the envelope. If more than one enclosure is in the envelope, list each on a separate line after the enclosure notation. For example,
It is also appropriate to only indicate the number of enclosures. This would be noted as "Encl:(3)."
Insert a copy notation two lines below the enclosure notation on the left-justified margin. Type the letters "CC:" followed by the names of all the people besides the addressee who are receiving the letter. Type each name on a separate line.