State the inputs
Enter 4H6H PJ1 with no designated wild rank. There are two natural cards in hearts and one substitute. Under our profile, the printed Joker can occupy 5♥.
Change one suit
Replace 6H with 6D. The natural cards now have different suits and different ranks. They cannot anchor one same-suit run or one equal-rank set under this profile, so the result is invalid.
Read the substitution list
The checker identifies which physical Joker is used and which missing position it fills. That list is one interpretation, not a list of new physical cards added to the hand.
A useful boundary
The tool is not choosing whether to retain the Joker, recommending a discard or evaluating the complete hand. It is explaining the group you supplied.