I’ve been wondering for a while, why for example sometimes in the middle of a quote in an article or even a book, there’ll be a a section of text or a phrase braced off. [Like this] and the passage that follows usually wouldn’t make sense if you didn’t have the braced bit. Why is it separated so? if it was only done in quotes I’d guess it was to fill in what the person being quoted poorly enunciated, but sometimes it starts off a sentence like I did earlier.
When it happens in quotes, it is something that the editor or author has inserted into the quote in order to make the meaning clearer, to compensate for the quote being out of context. For instance, if the quote had a pronoun like “he,” the quoting author might need to substitute the actual name in brackets, otherwise, the reader wouldn’t know to whom “he” was referring.
Quite simply, it is the standard technique to indicate what the person doing the quotation has added or changed to the original quotation to make it make sense. The exception, an italicized sic in brackets, indicates that the quoter is leaving the original as it was written, for whatever reason, even though it might be regarded as an error.
From your quoted remark above, imagine the last sentence quoted separately, and clarification added like this:
As you’ll notice, I supplied the initial capital I on “If” which you had left lowercase. In that case, it was a typo, but there are instances where a quotation will begin partway through a sentence, as in the following extract from the Declaration of Independence:
It’s used to indicate missing and/or modified material in a quote or, in the case of [sic], that the error or strange turn of phrase you are quoting is intentional.
For instance: I’ve been wondering […] why […] sometimes in the middle of a
[quote, article, or book]
, there’ll be a a section of text or a phrase braced off […] and the passage that follows usually wouldn’t make sense if you didn’t have [it] braced bit. [sic] Why is it separated so? [If] it was only done in quotes I’d guess it was to fill in what the person being quoted poorly enunciated, but sometimes it starts off a sentence like I did earlier.
Expanding slightly, anything inserted by the author/editor ('quoter") of what you’re reading that wasn’t in the original quoted text would go in brackets.
Sometimes, that’s explanatory material so that the text reads more clearly, as in Polycarp’s example, where an “it” or a “he” would be unclear without the earlier referenced nounc, so the quoter puts that noun in brackets so that no reader is confused… but, at the same time, that’s not exactly what the person quoted said.
Similarly, ellipses [ … ] to indicate omitted material may be put in brackets, although I’ve seen them used just in the quoted text without brackets.
But any other type of inserted editorial comment would also appear in brackets. The most common of these is the Latin [sic], meaning “thus”, when there’s some sort of error – grammar, spelling, fact – in the original quote and the quoter wants to make it clear that this is part of the original statement. Often a comment like [ bold facing mine ] to indicate that the quoter has emphasized with bold font something that the original quote did not.
And sometimes references. For instance, if I were quoting a long paragraph of Polycarp’s, and in that quote, he quoted a biblical verse without a cite, I might add the chapter/verse locator in square brackets.
So, it’s any material that the quoter has added or changed that was not part of the original quote.
Of course, when doing this, you have to make sure you do not change the message or the meaning of the quote. Bracketing text or omitting part of the quote should only be done for clairity and space, but without changing meaning.
One other use, rare but worth noting, is when letters aresupplied in paleography: a scrap of papyrus or a weathered inscription may require reading into the extant text to make it make sense. To use something people are relatively familiar with, imagine that the inscription at the base of the old statue referenced in the sonnet were an actual, weathered inscription. The paleographer might cite it as:
Clearly the left side of the inscription has weathered or chipped away to unintelligibility, but enough remains that what it said can be inferred.
Rare to find this sort of usage outside ancient-history circles, but it’s worth noting for completeness of this answer.
Looks like it’s been answered. But just to add a little: They do this a lot in newspapers. Often it’s to include more information. If someone says, “I love the work that Joe does,” and the article hasn’t yet introduced Joe, it might say “He said, ‘I love the work that [Chief of Police] Joe [Larson] does.’”