Reading an article by Texas A&M Professor Di Wang, "Mysterious Communication: The Secret Language of the Gowned Brotherhood in Nineteenth-Century Sichuan", tracing the specialized code-switching of one anti-Manchu/Qing secret society (published in the June 2008 ed. of Late Imperial China.) BRS had stumbled on to Di Wang's book on street culture in Chengdu, and we became engrossed in his faculty page.
One practice described is clandestine tea-ware arrangement paired with recitation of poetry - the graphic below, from the paper, illustrates a few for the budding revolutionary. A sample exchange may proceed as Wang describes:
If a member went to another lodge to ask for help, he would set up a “single whip formation” (danbian zhen), a teacup facing the mouth of a small teapot. If the host agreed to offer help, he would drink the cup of tea; if not, he would spill the tea on the ground and then pour new tea into the cup, drink it, and recite the poem, “A whipping horseman is running on the horizon, / Who’ll clear all clouds and come here alone. / Changing golden dragon shows fortune / And help our lord mount the throne.”(Wang 92)
William Stanton's The Triad Society or Heaven and Earth Association, full text online via Google Books, describes some of the other interactions you may see between lodge brothers loafing in wait for one another in the teahouse:
“Why is your hair so unkempt?/I was born under a peach tree”; “Why is your hair so ruffled?/I have been to extinguish a fire”; “Why is your hair so wet?/I have not long been born”; “Why has your hair got so many cobwebs in it?/They are not cobwebs, but five-colored silk.”