By virtue of office or position; "by right of office". Often used when someone holds one position by virtue of holding another: for example, the President of France is an ex officio Co-Prince of Andorra. A common misconception is that all ex officio members of a committee or congress may not vote – this may be the case, but it is not guaranteed by that title. In legal terms, ex officio refers to an administrative or judicial office taking action of its own accord, for example to invalidate a patent or prosecute copyright infringers.
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