The city council may consider issues in council executive sessions either in regular or special session in which the public may be excluded. That portion of the meeting in which the public may be excluded shall consider only those items that are permitted as outlined in RCW 42.30.110. Before meeting in executive session, the presiding officer shall state the general subject category necessitating the council executive session. All members of the city council, mayor and city staff shall hold in confidence all discussions concerning issues in the executive session and shall not discuss them outside of executive session except upon approval of the council. Violation of this section shall invoke disciplinary proceedings set forth in this chapter. (Ord. 972, § 20, 1989.)