The Open Packaging Conventions standard requires that the file name extensions of the files contained in a Descriptor are registered in the “[Content_Types].xml” file. Only file name extensions used in a Descriptor shall be present in the “[Content_Types].xml” file of the Descriptor.
A list of IANA registered content types is given in: https://www.iana.org/assignments/media-types/media-types.xhtml.
Table 2 gives some examples of file name extension content types.
Table 2 – Example of File Name Extension Content Types
|
File name extension |
Content type |
|
aml |
application/automationml-aml+xml |
|
amlx |
application/automationml-amlx+zip |
|
xml |
text/xml |
|
|
application/pdf |
|
png |
image/png |
The use of vendor-specific file name extensions is allowed. The vendor-specific file name extensions and content types may or may not be registered with IANA.