I see it frequently among regular bac players as well as read about it on other forums from time to time. These misunderstandings/mistruths have even been written into bac strategy, etc, etc.
The most frequent and debatable with the 'know it all's' are:
Banker having a 2 card 6 and the Players 3rd card is a 6 or 7, which forces the Banker to pull a 3rd card. Causes challenges the most.
The other two are:
Banker having a 2 card 5 and the Players 3rd card is a 4-5-6-7, which forces the Bankers to pull a 3rd card. Any other card for the Players 3rd card, causes the Bankers NOT TO PULL.
Banker having a 2 card 4 and the Players 3rd card is a 2-3-4-5-6-7, which forces the Bankers to pull a 3rd card. Any other card for the Players 3rd card, causes the Bankers NOT TO PULL.
There are no options to those pull/stand regulations. None whatsoever.