Answer:
there is smoke signs, sending letters by bird, then paying to have letters sent.
there is of course writing notes or messages into a stone wall or ground for later use or to leave for others.
i have read about people making sounds to communivate, whistling for calls, even making animal sounds to blend in.
ive personaly used hand signs for military use, or you could go on O block in blue clothing and throw some hand signs to communicate that you love this neighborhood.
Explanation:
