What is "inclusio"

In biblical studies, inclusio is a literary device based on a concentric principle, also known as bracketing or an envelope structure, which consists of creating a frame by placing similar material at the beginning and end of a section, although whether this material should consist of a word or a phrase, or whether greater amounts of text also qualify, and of what length the frames section should be, are matters of some debate. Inclusio is found in various sources, both antique and new. The purpose of an inclusio may be structural - to alert the reader to a particularly important theme - or it may be serve to show how the material within the inclusio relates to the inclusio itself. An important case of this occurs in the Gospel of Mark's treatment of the "Cursing of the Fig Tree" and the "Cleansing of the Temple" (Chapter 11). By giving the first half of the story before the Cleansing of the Temple, and the conclusion after, Mark creates a "frame" that effectively highlights that he wants the Cleansing of the Temple to be seen in light of the Cursing of the Fig Tree - ie. Jesus' actions in the Temple are not just a reform measure, but a judgement against it.