image/vnd.dwg

AutoCAD's native drawing format and the lingua franca of engineering documents, filed under image/ even though a DWG is a parametric CAD database, not a picture. The registration has a telling history: it was first proposed as image/x-dwg, then moved to the vendor tree because experimental x- names cannot be formally registered. Autodesk keeps the format closed and revises it with most releases, so the wider ecosystem reads DWG through reverse-engineered libraries; the file betrays its vintage in the first six bytes, an ASCII version code like AC1032 that changes per format generation — a version stamp, not a stable magic number.

.dwg is the binary drawing; .dxf is Autodesk's documented text/binary exchange sibling with its own type.

Defined by IANA registration — image/vnd.dwg · IANA registration. Registry facts from the IANA media-types registry via mime-db.