Comments/Ratings for a Single Item

The Prince may make a double step forward at its first move, if the intervening and destination squares are empty (like the Pawn).

I have just corrected the Interactive Diagram to implement this rule which was missing.

@HG: for the ID in this page, I had copied the one you had made for my book's appendix. Do you know why we have this line:

promoChoice=QF

The Pawn can only promote to the Q. So, I guess the F should be removed.

However, I understand that the F means the Prince here. So, I was expecting the ID to propose a promotion to Queen OR Prince (which it is not the rule), but only the Queen is proposed (which is the rule). How this is possible?

Thank you

The secret is the order of the pieces in the ID (and thus the piece table): the Prince comes first there, the Pawn second. So as far as the ID is concerned, the Prince is the only piece that promotes here (since maxPromote=1), and makes use of the promoChoice=QF when it does. The F is there because you have the choice to promote to Queen, or stay a Prince.

The promotions of Pawn and Ship don't involve any choice, and are taken care of by a JavaScript function WeirdPromotion() embedded in the page. The modern way of doing this would be to use morph parameters behind the definition lines of Pawn and Ship, to indicate their automatic promotions without the need for any scripting. Below the Pawn you could write the line

morph=Q

to indicate promotion to Q on the entire last rank. Below the Ship you would write

morph=E.........E

to indicate promotion to  Eagle in de corner squares.

There also was a JavaScript function BadZone() embedded in the page, which took care of forbidding the friendly capture of the King to capturing a Prince. This to allow such a capture as a means for entering a succession move. The modern way of doing that would be to define a captureMatrix that forbids all other friendly captures. Like

captureMatrix=///////////=..!11