You can update a meeting in Outlook without triggering notifications to all attendees. Here's how you can achieve this.Notice of any scheduled board meeting must be given at least 48 hours prior to the meeting. Some meetings, such as the annual meeting, require greater notice. This document is sometimes referred to as the charter. Some meetings, such as the annual meeting, require greater notice. A notice of meeting letter is a document that informs a group of people when and where their company is holding an assembly. On January 1, 2010, key changes to the Open Meetings. Act took effect to provide Illinois residents with a more open and accountable government. All school districts and cooperative agreements in Illinois have been required to provide official written notice to parents.