1. Introduction
Ho and Wong (2003) stated that, how information is shared among the participants deeply affects the function of capital markets. In business activities, investors require timely and correct information to reach effective investment decisions. This kind of information can be collected through many ways, and one of the most important resources is the corporations’ annual reports. The most important role of annual reports is to provide relevant, useful and reliable financial information to investors, shareholders and other interested people about the financial position and performance of the business as well as its future prospects to help users in decision-making. The information that has been supplied by annual reports towards their stakeholders includes two types: compulsory and voluntary information and compulsory disclosure is of more importance. Mandatory disclosure is a basic market demand for information that is required by various laws and regulatory bodies and has been ruled at