a) means for storing values of {HEAD ~ voltage and power measurements} made at {TAIL ~ the load}, 
made at
a ) means for storing values of { HEAD ~ voltage and power measurements } made at { TAIL ~ the load } ,
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH