16. The computer-implemented method of claim 15 , wherein sending the first expression to the second user further comprises: upon determining that the first and second users do not have a matching user classification, automatically identifying, based on a second user classification of the second user, a second expression corresponding to the first expression, wherein the second expression is distinct from the first expression and transmitted to the second user in lieu of the first expression, wherein the first and second user classifications are distinct classifications.
16. The computer-implemented method of claim 15 , wherein sending the first expression to the second user further comprises: upon determining that the first and second users do not have a matching user classification, automatically identifying, based on a second user classification of the second user, a second expression corresponding to the first expression, wherein the second expression is distinct from the first expression and transmitted to the second user in lieu of the first expression, wherein the first and second user classifications are distinct classifications. 17. The computer-implemented method of claim 16 , wherein the second expression is identified without requiring the first user to specify the second expression and without requiring the first user to specify the second user classification of the second user.