A while ago I read about ‘Hobo Marks’, they are simple marks that tramps etc would chalk onto a gatepost or wall to warn other tramps of any local danger (overzealous police), or let them know of any local benefits (generous householder). There are some examples here.
Anyway, I thought a similar system would be useful for those of us who work at a different agency every week, and rarely know what to expect – so I very quickly did a set of Hobo Marks For Freelance Graphic Designers. I expect to see them chalked outside certain agencies very soon.
Let me know in the comments if you think I’ve left anything out.