IIRC, the PTBNL was implemented for two reasons: 1) If the player you received played well, you gave up a better player, and vice versa. 2) You couldn't trade a player while they were on the DL (now IL), so the name was released when the player returned from injury. But the true "loan" idea is interesting, sneaky enough that if this was football, Bill Belichick would ty it. The Chiti deal was a curiosity at the time and will forever be the answer to a trivia question. Later