The 2nd line concerned the propellant maker (P. for Spandau's Pulverfabrik or Tr. to the powdermill at Troisdorf). The 3rd line mentioned the design of primer (Zdh, or zundhuetchen), the date of manufacture, as well as manufacturer; an "X" among the primer kind and date of manufacture indicated it absolutely https://spencerilkqm.theblogfairy.com/21707021/not-known-details-about-cci-rifle-primers