Ronon Dex receiving a tattoo.
A tattoo is a form of body modification, made by inserting indelible ink into the dermis layer of the skin to change the pigment. While they are relatively common adornments for the Tau'ri, tattooing is practiced by several cultures in the Milky Way and Pegasus galaxies.
History
In 2007, Ronon Dex was given a tattoo by Tyre. (SGA: "Reunion")