{HEAD ~ The most important parameters} are {TAIL ~ an azimuth angle} relative to a particular direction, a spatial frequency f or a number of grooves per millimeter, a relief profile shape, 30 and 
{ HEAD ~ The most important parameters } are { TAIL ~ an azimuth angle } relative to a particular direction , a spatial frequency f or a number of grooves per millimeter , a relief profile shape , 30 and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH