|Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact|
|Full name||Microsoft Compound File Binary File Format, Version 4|
The Microsoft Compound File Binary (CFB) file format is used for storing storage objects and stream objects in a hierarchical structure within a single file. See CFB_3 for a full description of the file system structure.
There are two active versions of CFB, version 3 and version 4. One major distinction between the versions is that the sector size for version 3 is of 512 bytes and the sector size for version 4 is 4096 bytes.
The minimum size of a compound file three sectors: one header, one FAT sector and one directory sector.
|Relationship to other formats|
|Has earlier version||CFB_3, Microsoft Compound File Binary File Format, Version 3|
|Has subtype||MSG, Microsoft Outlook Item|
Advanced Authoring Format (AAF) Object, Version 1.1.
Early versions of the AAF format detailed use of the structured storage systems outlined in CFB to store the objects on disk.
|LC experience or existing holdings|
|Licensing and patents||See CFB_3|
|External dependencies||See CFB_3|
|Technical protection considerations||See CFB_3|
|Filename extension||See related format.||See CFB_3|
|File signature||Hex: D0 CF 11 E0 A1 B1 1A E1
Hex: 0x0004 (version 4)
|From specification. This specification applies to the all Microsoft content types that share the general CFB structure.|
In addition to the Major Version field value declaration of the version number in the header, the Sector Shift field specifies the sector size depending on the version declaration. If Major Version is 4, then the Sector Shift must be 0x000C, specifying a sector size of 4096 bytes.