Mass meeting

In parliamentary law, a mass meeting is a type of deliberative assembly, which in a publicized or selectively distributed notice known as the call of the meeting - has been announced:

To the extent that persons in the invited category are clearly identifiable - as, for example, registered voters of a particular political party, or residents of a certain area - only such persons have the right to make motions, to speak, and to vote at the meeting, and none others need be admitted if the sponsors so choose. Attendees at a mass meeting are there under the implied understanding that the sponsors (who have engaged the hall and assumed the expenses of promoting the meeting) have the right to have the proceedings confined to the overall object they have announced. The assembled group of persons who are attending has the right to determine the action to be taken in pursuit of the stated object. "Membership" consists of all persons in the invited category who attend. If no qualification was placed in the call of the meeting, anyone who attends is regarded as a member and has the same rights as members in other assemblies - to make motions, to speak in debate, and to vote.

When it is desired to form a permanent society, the organizers proceed in much the same way as for a mass meeting, except that the meetings while the organization is being formed should usually be carefully limited to persons whose interest in the project is known. For this reason, it may be desirable to solicit attendance for these meetings by personal contact or by letter, rather than by public announcement. A series of meetings is usually held when organizing a permanent society.

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Wikipedia