Which of the following is NOT considered a prohibited article in cabin baggage?

Travel documents are not considered prohibited articles in cabin baggage because they are essential for a passenger's journey. Items such as passports, boarding passes, and other forms of identification are necessary for security clearance and to verify a traveler's identity at various stages of air travel. They play a crucial role in ensuring that passengers can proceed through security checks and board their flights legally and safely.

In contrast, items like guns, workmen's tools, and explosive substances pose significant security risks and are therefore prohibited in cabin baggage. These articles can potentially be used to harm others or compromise the safety of the aircraft, which is why stringent regulations restrict their presence on board. Understanding the distinction between necessary travel documents and items that threaten aviation security is vital for ensuring safe air travel.