Claudiu A

I don't understand this. My question is broad enough to be general (how should someone do something in some kind of situation, so that it is professionally acceptable). I summarise all of the answers in : it depends on culture and block meeting forward. I understand both, but I was expecting more than this.

@cdkMoose since you known there can be horrible business etiquette, it is important to know how they should be (opposite of horrible). Hence my question. I understand that in practice such rules sometimes don't apply, but it is still important to know what is right/wrong and why.

@thursdaysgeek The benefit is the following: I don't want to have a misperception on his actions if he either did not do anything wrong by participating, or did enough (should he approach me or something). I do not want to jump to conclusions about this colleague's professionalism, until I know how he should have handled this. I do not want to pass judgement because my common sense tells me that it is not ok to just attend in the meeting, but I might be wrong.

I understand what you are saying. This happens everywhere in day to day work.

As stated originally, it was not useful to invite that person (tech presentation, non-technical person). I am interested in regard with general business etiquette.

Thank you all for trying to find solutions. I do know I can set up meetings which cannot be forwarded. It would be nice if I got answers for the actual question.

The issue can be solved with a talk and an de-invite, but my question is more related to what is the professional approach from him, if he wanted to attend.

@Erik I agree, but we are a big multinational so the highest of standards are expected from us.

I am asking if there is a business etiquette for showing up to a meeting where the organizer did not invite you. (I could edit the question if I failed to ask clearly enough).