SLT modules use shell files. Typically, each shell file begins by importing common rules that apply to all
        topics. This set of common processing rules may in turn import additional common modules, such as those used for
        reporting errors or determining the document locale. After the common rules are imported, additional imports can
        be included in order to support processing for DITA specializations.</p>

      <p class="p">For example, XHTML processing is controlled by the <span class