What is considered common knowledge and how can it be distinguished from specialized or obscure information?

Common knowledge refers to information that is widely known and understood by the general public without needing to be cited. It includes facts like historical events, basic scientific principles, and well-known cultural references. Specialized or obscure information, on the other hand, is more specific and requires expertise or research to understand. To distinguish between the two, consider whether the information is widely known or if it is more niche and requires specialized knowledge to comprehend.