joebloggs: hey how's it going? donbonder: not too ba donbonder: d  'd' is the aim trailer
a letter or a pair of letters that remain in the entry box of an aim window when the typer prematurely presses send or enter
"joebloggs: hey how's it going? donbonder: not too ba donbonder: d  'd' is the aim trailer" What is the definition of "aim trailer"?