I point out that L68B2 is an endorsement for improper deception. To demonstrate consider this occasion:
N dummy, lead S
SAKJ
H-
SQxx s-
H- Hxxx
Sxxx
Upon the lead of a small spade, W returns his cards to the board and E objects immediately. It is ruled no concession and play resumes. Declarer spurns the finesse because the only valid reason for E to object is possession of the Q. This results in W collecting the SQ.
It is arguable whether declarer would finesse this occasion without the concession, or only sometimes. I argue that it is clear after the rejection that a thinking declarer would never finesse given the outburst of E asserting possession of a trick.
This situation is known as improper deception- yet it is endorsed by law…and ought not.