Special events are different from meetings and have different requirements, such as security.
The six elements that change a meeting to a special event are as follows:
1) If it is NOT sponsored by a bureau or office. Sponsors must attend, set up, and clean up the event.
2) If the organizers plan to have the meeting/event open to the public. That is, the public can come in during the meeting to participate. This does not, however,  pertain to members of the public participating in a panel or on a city-affiliated committee.
3) If the meeting/event is NOT City business - for example, a City employee wants to get married at City Hall.
4) If the meeting falls outside of public building hours, which are M-F, 8AM-5PM.
5) If alcohol will be served, where allowed.