The scientific meetings of the AU are the AU Symposia, AU Colloquia, Regional Meetings in Astronomy held under the auspices of the AU, the Commission Meetings, which may be Joint Meetings of Commissions, and AU Joint Discussions. This variety means that almost any demand for a meeting can be provided for by the AU structure, pro vided it is international in character, whatever may be the preferences of the proposers. The AU General Assemblies include Co ssion Meetings and Joint Discussions arranged by Commissions, together with the Invited Discourses, and it is these meetings that...