There are never enough explanations of the difference between communication and signification for the latter is a particularly challenging concept for students. The following seems to do well.
[S]ign activity takes place irrespective of specific functions and purposes, and therefore it is sometimes necessary to consider sign activity as a sort of idle, non-functional and unproductive semiotic mechanism.
From Susan Petrilli and Augusto Ponzio Thomas Sebeok and the Signs of Life in the series Postmodern Encounters edited by Richard Appignanesi.
And so for day 695