An implantable medical device, comprising: a housing including electronic circuitry; a header coupled to the housing and including a core, wherein the core defines a bore (50A; 50B; 50C), wherein the core includes: a superior surface, an inferior surface, and two side wall surfaces (64, 66) and a first face and a second face extending between the superior surface, the inferior surface, and the two side wall surfaces (64, 66); a receiving cavity (70A; 70B; 70C) adjacent to the bore, the receiving cavity (70A; 70B; 70C) configured to receive a first metal label (40A; 40B; 40C), wherein a first metal label (40A; 40B; 40C) including a first identifier is positioned in said receiving cavity; and a window (72A; 72B; 72C) that is in communication with the receiving cavity (70A; 70B; 70C), so that when the first metal label (40A; 40B; 40C) is inserted into the receiving cavity (70A; 70B; 70C), a portion of the surface of the first metal label (40A; 40B; 40C) is visible through the window (72A; 72B; 72C); wherein the implantable medical device further includes: a lead assembly including at least one lead (27A; 27B; 27C) having a distal end and a proximal end, the at least one lead (27A; 27B; 27C) including a second metal label (41A; 41B; 41C), the distal end including at least one electrode and the proximal end received within the bore (50A; 50B; 50C), wherein the second metal label (41A; 41B; 41C) includes a second identifier, the first identifier being substantially the same as the second identifier. a housing including electronic circuitry; a header coupled to the housing and including a core, wherein the core defines a bore (50A; 50B; 50C), wherein the core includes: a superior surface, an inferior surface, and two side wall surfaces (64, 66) and a first face and a second face extending between the superior surface, the inferior surface, and the two side wall surfaces (64, 66); a receiving cavity (70A; 70B; 70C) adjacent to the bore, the receiving cavity (70A; 70B; 70C) configured to receive a first metal label (40A; 40B; 40C), wherein a first metal label (40A; 40B; 40C) including a first identifier is positioned in said receiving cavity; and a window (72A; 72B; 72C) that is in communication with the receiving cavity (70A; 70B; 70C), so that when the first metal label (40A; 40B; 40C) is inserted into the receiving cavity (70A; 70B; 70C), a portion of the surface of the first metal label (40A; 40B; 40C) is visible through the window (72A; 72B; 72C); a superior surface, an inferior surface, and two side wall surfaces (64, 66) and a first face and a second face extending between the superior surface, the inferior surface, and the two side wall surfaces (64, 66); a receiving cavity (70A; 70B; 70C) adjacent to the bore, the receiving cavity (70A; 70B; 70C) configured to receive a first metal label (40A; 40B; 40C), wherein a first metal label (40A; 40B; 40C) including a first identifier is positioned in said receiving cavity; and a window (72A; 72B; 72C) that is in communication with the receiving cavity (70A; 70B; 70C), so that when the first metal label (40A; 40B; 40C) is inserted into the receiving cavity (70A; 70B; 70C), a portion of the surface of the first metal label (40A; 40B; 40C) is visible through the window (72A; 72B; 72C); wherein the implantable medical device further includes: a lead assembly including at least one lead (27A; 27B; 27C) having a distal end and a proximal end, the at least one lead (27A; 27B; 27C) including a second metal label (41A; 41B; 41C), the distal end including at least one electrode and the proximal end received within the bore (50A; 50B; 50C), wherein the second metal label (41A; 41B; 41C) includes a second identifier, the first identifier being substantially the same as the second identifier.