What is the purpose of brackets in a quotation?

These are used to indicate that a direct quote has been edited — to fit the surrounding information, or to add context that does not show up within the scope of the quote. This page has a more detailed description: Square brackets are used around words that are added that are not part of the original quote. read more

Brackets are used to reflect the direct quote has been edited. It is generally used to fit the surrounding information. read more

Square brackets are used around words that are added that are not part of the original quote. For instance, you might have a source that says "Brenda and David went to the store," but you only want the quote to refer to David as a pronoun in your quote. read more

When writers alter words in a direct quotation, square brackets —[ ]—are placed around the change. The brackets, always used in pairs, enclose words intended to clarify meaning, provide a brief explanation, or to help integrate the quote into the writer's sentence. read more