The latching means 18, 19 have {HEAD ~ guide edges} 20 in {TAIL ~ their regions} facing the closing part 16 
in
The latching means 18 , 19 have { HEAD ~ guide edges } 20 in { TAIL ~ their regions } facing the closing part 16
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH