Placement of period in quotation or definition at end of sentence (American rule)

The American rule for sentences ending in a quotation is that the period should be inside the closing quotation mark. The rule for parentheticals at the end of a sentence is that, when the parenthetical is not itself the full sentence, the period should go outside the closing parenthesis.

My question is about the interaction of these rules -- the placement of a period when a sentence ends with quotation marks inside a parenthetical that is not, itself, a full sentence. My question therefore differs from this question. It's quite close to this one, but neither the questions nor answers there discuss the American rule and its not clear if anyone considered it.

I'm most interested in the case of the first use of a defined term, but am also wondering if the rule is any different for other parentheticals.

Here are two examples with the first use of a defined term in quotation marks. They are written here with the period inside the closing quotation mark.

Compensation of injured employees is addressed by the Illinois Workers Compensation Act (the "Act.")

Before reunification, Germany was divided into two states, the German Democratic Republic ("DDR") and the Federal Republic of Germany ("BDR.")

And here's an example with a longer quote inside a sentence ending parenthetical:

After the third glass, I began to see things as they really were (which, in the words of Oscar Wilde, is often "the most horrible thing in the world.")

(I realize that the parentheses in the last example could, and probably should, be eliminated, but then it wouldn't be much of an example.)

All of these examples, as written, look wrong to me. But I've been indoctrinated to the American rule, so the alternative also seems wrong.

I suspect that if I owned the Chicago Manual of Style, I'd find the answer there.

Solution 1:

This currently seems to be in flux. In the bad old days it was determined by the layout people. A period outside of a set of quotes all by itself offended their tidy nature. Periods, exclamation marks, question marks always went inside quotes and, I think, parentheses.

More recently the trend is to put the period with the most recent full sentence.

The computer revolution with hoards of people writing code means that a lot of people see punctuation as syntactic elements. If you are quoting a full sentence, then the period goes inside the quotes, otherwise, outside.

I've even seen (though rarely)

Michael said as he went out the door, "I'm going to town later today.".

where the first period finishes the quote, and the second period finishes the sentence.

This, right now, is style. Find which guide you care about, and check with it.