zip mime types, when to pick which one

So far for Mime Types for Zip files I've seen:

• application/octet-stream
• multipart/x-zip
• application/zip
• application/zip-compressed
• application/x-zip-compressed

I guess my question is which is the "best" and why? Why is there so many开发者_如何转开发 choices? I use winrar and it doesn't seem to care what the Mimetype is, but WinZip seems to only like multipart/x-zip and application/octet-stream. is there a Mimetype I can have all Zip files be downloaded as that will work in all programs?

thanks!

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Registered with IANA MIME type is application/zip : http://www.iana.org/assignments/media-types/application/zip

WinZip is not a reference implementation (since originally ZIP standard is developed by PkWare).

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Some facts about MIME types

• MIME types follow a format: media-type/subtype-identifier. Example: image/png.
• IANA maintains a list of all registered media types and subtypes.
• The x- prefix of a subtype-identifier indicates that it is experimental and non-standard (not registered with IANA).

Now about the zip specifically...

• application/zip is a standard MIME type for zip files, officially registered with IANA. It seems like a good first choice :)
• application/octet-stream is defined in RFC 2045 and 2046: The “octet-stream” subtype is used to indicate that a body contains arbitrary binary data, so the content can be anything, not just zip.
• multipart/x-zip - unlike a “discrete” type, the “multipart” type is one which represents a document that's comprised of multiple component parts, each of which may have its own individual MIME type. I suspect that the logic here is that a compressed file consists of multiple files. Thus, zip fits the “multipart” definition. But to me, it looks like overinterpretation, I would expect plain-text delimiters between parts to classify content as multipart. Moreover, it's not registered as a standard.
• application/zip-compressed - a non-standard type, the naming violates RFC2046: A media type value beginning with the characters “X-” is a private value, to be used by consenting systems by mutual agreement. Any format without a rigorous and public definition must be named with an “X-” prefix
• application/x-zip-compressed - some non-standard convention, I'm not sure if there is any significant usage
• application/x-zip - some non-standard convention, I'm not sure if there is any significant usage