== "Heavy" in aviation callsigns == 

 The AIM page you cite does indeed say that B757 aircraft are treated as heavy for wake turbulence avoidance purposes, but seems to say that they don't use the word "heavy" in their callsigns. This matches my (admittedly, not so recent) experience: they may get heavy aircraft separation, but they don't use "heavy" on the air. Have you heard differently, or have a more concise reference?