This article is originally taken from Media Streams on Squid wiki, I am just posting it here for quick reference.
Media Streams come in many types. Most commonly used are Audio, Video, or Audio-Visual Streaming.
It’s hard to separate the stream types by application so the config below includes all the known streams and simply comments the commonly known ones where possible.
Squid Configuration File
# Media Streams
## MediaPlayer MMS Protocol
acl media rep_mime_type mms
acl mediapr url_regex dvrplayer mediastream ^mms://
## (Squid does not yet handle the URI as a known proto type.)
## Active Stream Format (Windows Media Player)
acl media rep_mime_type x-ms-asf
acl mediapr urlpath_regex \.(afx|asf)(\?.*)?$
## Flash Video Format
acl media rep_mime_type video/flv video/x-flv
acl mediapr urlpath_regex \.flv(\?.*)?$
## Flash General Media Scripts (Animation)
acl media rep_mime_type application/x-shockwave-flash
acl mediapr urlpath_regex \.swf(\?.*)?$
## Others currently unknown
acl media rep_mime_type ms-hdr
acl media rep_mime_type x-fcs
http_access deny mediapr
http_reply_access deny media