Each second slotted partition 14 has {HEAD ~ a first or bottom edge} 18, {TAIL ~ a second or top opposed edge} 20 and a pair of side edges 22 
Each second slotted partition 14 has { HEAD ~ a first or bottom edge } 18 , { TAIL ~ a second or top opposed edge } 20 and a pair of side edges 22
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH