Which of the following describes an out-of-order amendment?

An out-of-order amendment is one that does not pertain to the subject matter of the main motion being discussed. This is significant because parliamentary procedure requires that amendments relate directly to the topic at hand to maintain focus and coherence in discussion. If an amendment is unrelated, it diverts the assembly from the issue under consideration and can lead to confusion and disorganization in the debate.

The other choices highlight other important aspects of amendments but do not define an out-of-order amendment accurately. For instance, an amendment that is too broad may still be relevant to the main motion but lacks the necessary specificity. An amendment proposed at an inappropriate time could disrupt proceedings, yet it does not inherently mean the amendment itself is unrelated to the main motion. Lastly, a duplicate amendment may repeat existing provisions but can still be relevant to the topic being discussed. Thus, the correct identification of an out-of-order amendment hinges on its lack of relevance to the current main motion.