Abstract
Information classification is aimed to secure the documents from being disclosed. The information is classified according to their critical semantic. The decision of classifying a portion of the document as a ‘secret’ depends on the effect of its disclose in the organization the document written for. However, understanding the semantic of the document is not an easy task. The rhetorical structure theory (RST) is one of the leading theories aimed for this reason. In this paper, we will explain a technique to classify the information using RST.