dotx A .dotx extension file is a document template file where the x stands for XML (eXtensible Markup Language). The DOTX template files are created using the Microsoft Word Processor. They can either be content templates or layout template to suit custom needs. A DOTX template includes information on the auto text, settings, layout of the document, toolbars and macros. There are some standard .dotx format templates provided by Microsoft but users have the option to create customized templates as per required specifications for business correspondence including envelopes, letters, newsletters, training material, forms, brochures, announcements as well as for legal documents that include contracts and agreements.