number (usually in the ear, or on the inner thigh) via which their owners can be identified. However, the use of a microchip has become an increasingly popular choice and since 2016 is a legal requirement for all 8.5 million pet dogs in the UK. Cosmetic Permanent makeup is the use of tattoos to enhance eyebrows, lips (liner and/or lipstick), eyes (liner), and even moles, usually with natural colors, as the designs are intended to resemble makeup. A growing trend in the US and UK is to place artistic tattoos over the surgical scars of a mastectomy. "More women are choosing not to reconstruct after a mastectomy and tattoo over the scar tissue instead... The mastectomy tattoo will become just another option for post cancer patients and a truly personal way of regaining control over post cancer bodies..." However, the tattooing of nipples on reconstructed breasts remains in high demand. Medical Medical tattoos are used to ensure instruments are properly located for repeated application of radiotherapy and for the areola in some forms of breast reconstruction. Tattooing has also been used to convey medical information about the wearer (e.g., blood group, medical condition, etc.). Alzheimer patients may be tattooed with their names, so they may be easily identified if they go missing. Additionally, tattoos are used in skin tones to cover vitiligo, a skin pigmentation disorder. SS blood group tattoos () were worn by members of the Waffen-SS in Nazi Germany during World War II to identify the individual's blood type. After the war, the tattoo was taken to be prima facie, if not perfect, evidence of being part of the Waffen-SS, leading to potential arrest and prosecution. This led a number of ex-Waffen-SS to shoot themselves through the arm with a gun, removing the tattoo and leaving scars like the ones resulting from pox inoculation, making the removal less obvious. Tattoos were probably also used in ancient medicine as part of the treatment of the patient. In 1898, Daniel Fouquet, a medical doctor, wrote an article on "medical tattooing" practices in Ancient Egypt, in which he describes the tattooed markings on the female mummies found at the Deir el-Bahari site. He speculated that the tattoos and other scarifications observed on the bodies may have served a medicinal or therapeutic purpose: "The examination of these scars, some white, others blue, leaves in no doubt that they are not, in essence,