"Conventions" and "delegates" are words used by the WTS that mean different things at different times and are almost always different to the usage outside of the WTS. Generally, a delegate is one sent as a representative of another one or body often with responsibility or power to act for the ones who sent the delegate. In WTS terms all convention attendees are delegates even though they are not representing anyone else, certainly have no authority and will not engage in discussion with others to set agendas, agree actions, or make decisions.
In the case of special International conventions certain ones can attend and be assisted in travel and with accomodation. They have no special responsibility and hardly represent anyone other than act as "goodwill" ambassadors for their particular region. The WTS can set the requirements for who can be "delegates" to these events and to whom such special arrangements will be granted. However, most conventions are open to the public and any congregation member can attend if they are willing to make their own travel arrangements. They won't be official, Society approved "delegates" they'll just be regular "delegates" like everyone else.
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