Follow up: The funkandwagnalls site is not responding. From one of my "bricks & mortar" sources (1963):

In American usage printers usually place a period or comma inside closing quotation marks whether it belongs logically to the quoted matter or to the whole sentence or context. <The package is labeled "Handle with Care."> [further example]

But when a logical or exact distinction is desired in specialized work in which clarity is more important than usual, a period or comma can be placed outside quotation marks when it belongs not to the quoted matter but to a large unit containing the quoted matter. <The package is labeled "Handle with Care".> <The Prime Minister, after reporting the negotations, declared resolutely, "Our only course is to resist aggression".> < Replying with the one word "Bunk", he subsided.>

[I question whether the next-to-last example is correct.]