Nowadays hobos probably use cellphones and email to communicate. Things were different in the early years of the last century. The original american hobo knew the meaning of the signs, which were written with chalk or coal on fences, sidewalks and buildings. A secret language, a code, left for him by a brethren hobo. It warned him about danger and tips to free meals as well, anything to make life a little easier.

If you would like to learn more about the meanings of the different signs, check out these websites for background information:

Signs of the hobos
www.canadiangeographic.ca/Magazine/MA01/hobolisting.html

Gallery of signs, plus a glossary of Hobo terms
www.worldpath.net/~minstrel/hobosign.htm

www.warchalking.org