The Internet Working Group's Request for Comments #1521 paper specifies the content types and content subtypes for multimedia attachments.

SOLUTION:

Listed below are the MIME Media type and subtype; this information is useful in configuring your browser's helper apps. Your browser may ask you to enter Type and Subtype separately, or in the format Type/Subtype

Type		Subtype

text		plain 
		richtext 
		enriched 
		tab-separated-values	

multipart	mixed
		alternative
		digest
		parallel
		appledouble
		header-set

message		rfc822
		partial
		external-body
		news

application	octet-stream
		postscript
		oda
		atomicmail
		andrew-inset	
		slate
		wita
		dec-dx
		dca-rft
		activemessage
		rtf
		applefile
		mac-binhex40
		news-message-id
		news-transmission
		wordperfect5.1
		pdf
		zip
		macwriteii
		msword
		remote-printing
	
image		jpeg
		gif
		ief
		tiff

audio		basic

video		mpeg
		quicktime