{HEAD ~ The microscopic relief structure} 4 is an optically effective grating with parallel straight or curved grooves and at least locally involves {TAIL ~ a periodic structure} which is described by the parameters thereof 
{ HEAD ~ The microscopic relief structure } 4 is an optically effective grating with parallel straight or curved grooves and at least locally involves { TAIL ~ a periodic structure } which is described by the parameters thereof
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH