What is a non-elected officer and where can I find some interesting facts?
The Clerk of the House of Representatives.

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Description
A woman in a suit with a gown over it is standing at a desk in the House of Representatives reading from a piece of paper. A Despatch Box and microphone are in front of her. Behind her the Speaker is sitting in his elevated chair.
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Thank you for your question, Lee.
In addition to members of parliament—who are elected representatives of the people—non-elected officers also work in the Senate and House of Representatives. Non-elected officers are parliamentary employees who have a range of important responsibilities and duties to make sure the Australian Parliament can do its work.