I have prearranged with London always to add 3 to the first letter and 2 to the fourth.

He was to add 4 to the second letter and 3 to the third.

Instead he'd added 19 to the second letter and 20 to the fourth.

He should have added 2 to the second letter of his indicator-group and 3 to the third.

Instead he'd added 4 to the fourth letter and 5 to the fifth.

In cases where the piece is ambiguous, the starting square is added to the letter for the piece.

He added a line to the letter about the money and the instructions to come back with Henri.

If it had been a bellhop or a waiter, Terry would have added a line to the letter and said so.

Why, then, did the members decline to add Carnegie Hall's name to the letter?

That adds a note of authenticity to the letter.