You need to add additional MIME types (other than those listed and specified in the object list in the VPM), but don't see any options to do so.
You have to add this in the local policy instead of the VPM. As the VPM is already pre-defined, you can't add or edit the MIME types in the list. Follow the instructions below to add additional MIME types by using the local policy :
To add MIME types:
<Proxy>
response.header.Content-Type="Video/mp4" Allow
If you need to add more MIME type, then just add the types below the rule as per below** :
<Proxy>
response.header.Content-Type="Video/mp4" Allow
response.header.Content-Type="Video/flash" Allow
Then, install the policy.
**Note that "video/mp4" or "video/flash" is the mime type and edit as per what is needed.