Cardfile (sometimes spelled CardFile or Card File) is an address book application, with a native .crd file format. It was included with Microsoft Windows 1.0 through Windows Me and Windows NT 4. It has apparently been used as a clip art format.
Reportedly, the Cardfile source code was included in some Windows SDKs.
There are three known .crd file formats, which can be named after their signatures:
- "MGC" format
- "RRG" format, used when the file contains OLE 1.0 objects
- "DKO" format, which uses Unicode text
Files begin with ASCII "
RRG", or "
- Archived copy of Q99340: Windows 3.1 Card File Format
- Microsoft Support: Windows 3.1 Card File Format (from archive.org)
- The Cardwin Project website - Has information about the format
- The Cardwin Project
- Freeware 64 bit and 32 bit CardFile replacement
- Deark can extract images and text, in most cases
- WINDOART.ZIP [Ed. note: Somebody confused CRD format with CDR format.]