A reader wrote and asked me whether the phrase “attorney-client privilege” or “attorney-client privileged” was correct. I gave her my answer and told her that I would write a blog post on it.
“Attorney-client privilege” is defined as “the requirement that an attorney may not reveal communications, conversations and letters between himself/herself and his/her client, under the theory that a person should be able to speak freely and honestly with his/her attorney without fear of future revelation.” (http://dictionary.law.com/default.aspx?selected=2467)
“Attorney-client privileged” would be used if you were talking about an “attorney-client privileged communication” or “attorney-client privileged information.”
I did find a law firm article (http://www.faegrebd.com/the-holey-grail-a-guide-to-attorney-client-privilege) indicating memos containing privileged information should be marked “ATTORNEY-CLIENT PRIVILEGED AND CONFIDENTIAL.” This makes sense because you are talking about the information in the memo, which is attorney-client privileged information (as mentioned above) and is confidential information.
So, if you are indicating on a memo or on a letter that the information is confidential and subject to the attorney-client privilege, the correct designation appears to be “ATTORNEY-CLIENT PRIVILEGED INFORMATION.” It follows that you could say that the word “information” is assumed and “ATTORNEY-CLIENT PRIVILEGED” is a correct designation.
When you are talking about the privilege and not the information, then “attorney-client privilege” is proper, but if you are talking about information or a specific communication, then “attorney-client privileged” is correct.
This research proved that my original answer to the reader was . . . wrong! But now I know and will be able to figure out if we are talking about the privilege or the communication so that I get it right.