<messaging> (BCC) An electronic mail header which lists
addresses to which a message should be sent, but which will
not be seen by the recipients.
Bcc is defined in RFC 822 and supported by most e-mail
systems. A normal, non-blind "CC" header would be visible to
all recipients, thus allowing them to reply to each other as
well as to the sender. According to RFC 822, the addresses
listed in a BCC header are not included in the copies of the
message sent to the recipients. RFC 822 says BCC addresses
may appear in the copy sent to "BCC" recipients themselves
(though this would be unusual).
