application/msword

The binary Word format of 1997-2003, and the type people still reach for when they mean any Word file — a .docx served as application/msword is the single most common Office mislabel. Inside is an OLE2 compound file, a little filesystem-in-a-file specified by [MS-CFB], and its d0 cf 11 e0 signature is shared byte-for-byte by binary Excel, binary PowerPoint, MSI installers and everything else built on the container. The magic listed here therefore proves only compound file, not Word; identifying Word specifically means finding the WordDocument stream inside.

.dot templates share the type; the modern .docx is a different type entirely.

Defined by [MS-DOC] — Word (.doc) binary file format · IANA registration. Registry facts from the IANA media-types registry via mime-db.