In regard to those times when you are not sure if the information you are using is common knowledge,your text suggests that you should

Question

Quizplus · Accepted Answer

The best choice in this situation is to err on the side of caution and document the source of the information, even if you are not sure if it is common knowledge. This will prevent accusations of plagiarism or intellectual property theft. Omitting the source or using different information is not a reliable solution, and contacting the author for approval may not be feasible or necessary in all cases.

In Regard to Those Times When You Are Not Sure