The rules of procedure for conference sessions of Council shall be:
(a) Council shall meet in conference session prior to the regular meeting of Council;
(b) The Mayor may call Council together for a conference session at any time;
(c) The conference session shall be devoted exclusively to any matters regarding which the interchange of information preliminary to public discussion is deemed to be essential;
(d) Any matter under discussion shall be regarded as confidential; and
(e) No formal vote shall be taken on any matter under discussion, nor shall any Council member enter into a commitment with another respecting a vote to be taken subsequently in a public meeting of Council; provided, that nothing herein shall prevent a polling of Council, or the taking of an informal vote, on any matter under discussion.