I was challenged on my advice to use 456 before the question mark. Rule VI§38 says that a punctuation indicator is not used at the beginning of a braille line or after a space. In those circumstances the mode of punctuation is considered to be literary. Thus, if we follow the literary rules, BF Rule 6§1b says a dot 4 should be inserted before a freestanding punctuation mark. I apologize for my error.