Final answer:
The term 'PROTOCOL' refers to a formal or official set of rules or code of behavior that must be followed in a particular situation, like the practice in a town where inhabitants do not speak to one another after dark.
Step-by-step explanation:
The word PROTOCOL in the sentence "It was PROTOCOL for all inhabitants in the town to not speak to one another after dark." refers to the accepted or established code of behavior in any organized institution, group, or situation. In this context, it implies that there was a formal or official rule in the town that dictated the behavior of its inhabitants regarding not speaking to each other after dark. This would be similar to formalities and societal expectations observed in various historical and fictional accounts where characters must adhere to certain behaviors to maintain order and respect among different ranks and statuses. Examples include the compulsory deference expected in hierarchical societies or during specific rituals or routines that were practiced uniformly by a group or in certain areas, demonstrating the societal and cultural importance of protocol in maintaining structure.