You can add proper after a word to indicate that you are referring to the central and most important part of a place, event, or object and want to distinguish it from other things that are not regarded as being important or central to it.
双语例句
例： A distinction must be made between archaeology proper and science-based archaeology.
必须对严格意义上的考古学和以科学为基础的考古学加以区分。