application/smil		smil,smi	Synchronized stream
application/vnd.rn-realmedia	rm		RealMedia stream 
audio/vnd.rn-realaudio		ra		RealAudio stream
audio/x-pn-realaudio		ram,rmm		RealPlayer metafile
image/vnd.rn-realflash		rf		RealFlash stream
image/vnd.rn-realpix		rp		RealPix stream
text/vnd.rn-realtext		rt		RealText stream
video/vnd.rn-realvideo		rv		RealVideo stream