My grandfather's cousin , FRANCIS JOHN MEATS , from Pontypridd , was also killed in the Battle of Mametz Wood , on the 10th of July , and his name is on the Thiepval Memorial . The Memorial commemorates " the missing " , however I find this term misleading . During the 1st World War , when a soldier was killed in action , it was , under Governments orders , customary to remove the identifying "dog-tags " from those killed . They were either removed by those fighting with them if they were able to or by soldiers who were specially selected to leave the trenches under cover of darkness , when the fighting stopped , to gather them from the fallen . The original idea was to return them to the soldiers loved ones , however they were not , maybe because there was such a huge death toll . It became apparent later that this was such a bad idea when they realized that they could not identify the bodies when it came to burying them , hence the MISSING are not actually missing , they know who they are from the names on the removed dog-tags , they are actually the UNIDENTIFIED