an Entity references as follows:
Mail merge consists of combining mail and letters and pre-addressed envelopes or mailing labels for mass mailings from a form letter. This feature is usually employed in a word processing document which contains fixed text (which is the same in each output document) and variables (which act as placeholders that are replaced by text from the data source word to word). Some word processors can insert content from a database, spreadsheet, or table into text documents.