In the spite of explosive growth of the Internet, information relevant to users is often unavailable even when using the latest browsers. At the same time, there is an ever-increasing number of documents that vary widely in content, format, and quality. The documents often change in content and location because they do not belong to any kind of centralized control. On the other hand, there is a huge number of unknown users with extremely diverse needs, skills, education, and cultural and language backgrounds. One of the solutions to these problems might be to use standard terms with meaning; this can be termed as controlled vocabulary (CV). Though there is no specific notion of CV, we can define it as a set of concepts or preferred terms and existing relations among them. These vocabularies play very important roles classifying the information. In this chapter, we focus the role of CV for publishing the web of data on the Web.