This badge is for those Sisters who have a tattoo or two. Many Sisters share that fact with other Sisters (or it's very obvious) and other Sisters choose to keep theirs hidden. Either way, let this patch let the world know you, Sister on the Fly, have a special mark somewhere on your wonderful body.
Butterfly, unicorn, fishing fly, bug, flower, heart, paw print, stars, portrait, tribute, name, words, dates, the SOTF logo or letters—
you tell us!
(Wonder if this will suffice for any Sister with piercing, too?)