Beginning with the framework established by Haugen (1983) as a basis for this review, corpus planning can be defined as those aspects of language planning which are primarily linguistic and hence internal to language. Some of these aspects related to language are: 1) orthographic innovation, including design, harmonization, change of script, and spelling reform; 2) pronunciation; 3) changes in language structure; 4) vocabulary expansion; 5) simplification of registers; 6) style, and 7) the preparation of language material (Bamgbose 1989). Jernudd (1988) provides a more detailed discussion of these linguistic aspects of language planning. Although the creation of these language related materials often requires intense linguistic activity, the focus of this review is not on linguistic description, but rather on historical and sociolinguistic studies which illuminate corpus planning processes. These processes can be divided into two categories: those related to the establishment of norms, and those related to the extension of the linguistic functions of language. In his revised model, Haugen labels the former category, Codification or standardization procedures, and the latter, Elaboration or the functional development of language. These categories form the two major sections for this review.