This document discusses how to perform a mail merge in PageMaker 7.0. It explains that mail merge allows you to combine a data source containing mailing addresses with a main document. The data source is organized in a tabular format with field names like registration number, name, and class. These merge fields can then be used in the main document and dynamically populated from the data source during the merge. The steps include creating the main document in PageMaker, specifying the Excel data source, and merging the data to automatically populate the fields.