A resolution is required to exclude the public and press from an agenda item, even if no public or press are present. The resolution should outline the nature of the matter to be discussed, without divulging any confidential information.
The minutes of the meeting must record the decision made, but without divulging any confidential information. In other words, if a contractor is being appointed, the name of the chosen contractor and outline of the contract should be made public, but the details of the unsuccessful bidders need not be. For legal and staffing matters, there may be a fine line between recording the decision of the council and not sharing too much information.