This is a very good question and I can only answer it this way: 19 Again I truly say to YOU, If two of YOU on earth agree concerning anything of importance that they should request, it will take place for them due to my Father in heaven. 20 For where there are two or three gathered together in my name, there I am in their midst." - Matt. 18:19, 20. Many congregations were formed with just a few persons present. My understanding is always pray to Jehovah through his Son Christ Jesus before each meeting, large or small, and Jehovah's Holy Spirit will guide you.
A semi-formal meeting the public is typically invited to attend and listen to the speakers. Semi-formal meetings use some of the procedures of a formal meeting.
Formal meetings are preplanned with a specific set of topics to be discussed and certain objectives as well as a specific agenda. Informal meetings are not as planned out as formal meetings and are often last minute meetings.
In a formal meeting, you say, "The meeting is adjourned."
In the context of a formal meeting, an 'apology' refers to prior request to be absent from a meeting. It simply means, that the members are aware of your absence.
Formal and Informal.
It depends on what you mean when you are referring to as a formal meeting.
This is hearsay, which is a secondary source of information that is not allowed.
A formal meeting is a preplanned meeting. It has a predetermined set of topics that one wishes to discuss along with a set of objectives that one wishes to achieve at the end of the meeting. At a formal meeting, generally it is a senior executive who presides over the affair. The members of the meeting are often given a considerable period of notice before the meeting, preferably through formal means such as memos. As the title suggest, the atmosphere in such meetings is generally somber, formal. Informal meetings are generally not planned well in advance. The members are not notified through formal means. They generally take place in neutral surroundings, for example in a restaurant rather than a boardroom.
convene
lobsters backs
so they can get busy
The term is "informal" witnessing. Everyone knows Jehovah's Witnesses go formally knocking on people's doors hoping to be allowed to give a witness for their beliefs. That is the formal, or usual way of witnessing. But if you and one of Jehovah's Witnesses meet you on the street or in a store and you strike up a conversation, they can give a witness for their beliefs 'informally'.