Microsoft Word template
MS Word Dot format is variant of the DOC format used in (pre-2007 versions of) Microsoft Word. It is nearly identical to the DOC format, but causes Word to treat it as a template rather than a standalone document, meaning that when you open it, make changes, and save it, it will not automatically save on top of the original file, but will prompt for a new filename to save to, in DOC format by default (though you can use other "Save-As" options to save as different things including DOT). The purpose is to save formatting templates to use as starting points for creating documents; for instance, you may have a template for business letters. In Word 2007 and later, DOTX is used instead, as the template version of the DOCX format. (Also, DOTM is a variant of DOTX supporting templates.)