The description of dotm format expansion
The dotm file is a template of the document, being created in the text editor Microsoft Word. Contains layout, settings and macro-elements of the document, set up by default. Applied during the creation of the new docm document with embedded macro-elements.
The dotm files can be used in order to create numerous documents with embedded macro-elements, applying the same basic formatting. This format was primarily added to Microsoft Word 2007 release.