Content-Disposition
The Content-Disposition header, which is borrowed from RFC 1806, allows for some additional flexibility with regard to media types. The most common use of this header is to force a filename for a file that should be saved rather than rendered. An example of this use is the following:
Content-Disposition: attachment; filename=”example.pdf”
This indicates that the user should be prompted to download the file and that the pre-filled filename should be example.pdf.
Note
This technique can also resolve the browser flaw mentioned previously, where the file extension is used to determine media type instead of the Content-Type entity header. Thus, Content-Disposition can allow the true filename of the resource to be overridden.
For cases where the resource is intended to be inline, including resources such as streaming media, a format similar to the following can be used:
Content-Disposition: inline; filename="playlist.m3u"
Content-Disposition, combined with a proper Content-Type header, provides the developer absolute control over the interpretation of the resource’s media type.