The terms which comprise an entry in an index can be arranged in various ways. The use of roles or facets such as ‘thing - action - part - effect’ under which terms can be categorised, allows the use of citation orders which preserve the syntactic relationships between terms in a string. Alphabetization, and rotation in context, are simple methods but with certain disadvantages for the users. The citation order of B.T.I, results in a detailed index using punctuation to indicate relationships. PRECIS incorporates prepositions which preserve the context when strings are shunted to create the necessary entries. Articulated indexes use natural language phrases displayed under selected subject headings. These methods could be used to construct book indexes.