I used to be an active Hasher (Hash House Harrier - you know, that drinking group with a running problem), and that's exactly how they communicate in a crowd of strangers. If any one of them is searching out like compatriots they say or yell out "Are you?" and the responding party responds with "On-On!".
Maybe when in a group of the finely tattooed we need to loudly work the words "Last Sparrow" into our conversation and see whose ears perk up . . .