{HEAD ~ The multimedia content} may be layered using {TAIL ~ multiple different layering approaches} simultaneously, and access to the different types of layers may be offered simultaneously 
layered using
{ HEAD ~ The multimedia content } may be layered using { TAIL ~ multiple different layering approaches } simultaneously , and access to the different types of layers may be offered simultaneously
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH