DOC

MS Word Doc format is a family of formats used by older versions of MS Word (they now use DOCX). Wikipedia says the following four types exist
 * Word for DOS
 * Word 1 & Word 2 for MS Windows, and Word 4 & 5 for Mac
 * Word 6 & Word 95 for MS Windows, and Word 6 for Mac
 * Word 97, 2000, 2002, 2003, 2007 & 2010 for MS Windows, and Word 98, 2001, X, & 2004 for Mac