censhare differentiates between File types and MIME types.

A File type in censhare terminology describes the functional role of a given storage item of an asset. The MIME type describes the technical format (or media type) of a storage item. For example, a TIFF image is stored in the censhare system, the Application Server automatically renders a JPEG preview of the image. The asset now contains two storage items: one storage item of File type "master" and MIME type "image/tiff" and one storage item of File type "preview" and MIME Type "image/jpeg".

Whenever a file is imported into censhare, the system tries to identify the MIME type of the file and stores this information in the database as metadata of the storage item. Additionally, MIME types can be associated with asset types, which allows the system to automatically set the asset type of a new asset (existing assets will not update their asset type, though, when the MIME type of the master file changes).

censhare can only identify MIME types that were defined in the Master Data. The system comes with more than 80 pre-set MIME type definitions in the Master Data and new MIME types can be added by customization.

In the process of identifying MIME types, censhare first analyzes the file content, applying so-called Magic numbers (resp. Magic byte patterns in censhare terminology). If this file content analysis fails, the MIME Type is determined from the filename extension. Files on Macintosh platforms are additionally probed for their MacType and MacCreator signatures. If the MIME Type can not be identified, a generic "application/x-unknown" MIME Type is applied.

MIME (Multipurpose Internet Mail Extensions) Types were originally invented for describing media types in email attachments, but are now commonly used for a lot of protocols including HTTP, RTP, and SIP. The MIME Type is composed of at least a type and a subtype. 

For more information, see the list of MIME Types that is maintained by the Internet Assigned Numbers Authority (IANA).

We strongly recommend to use the IANA specifications when new MIME Types are defined in the censhare Master Data.