In written documents of various types, parentheses are also used around numbers and letters in connection with various lists, numbered examples in a text such as this one, etc.Here is an example of what this may look like: In academic writing, parentheses are also used (in some reference systems) both when we refer to our sources in the text and in our reference lists or bibliographies.“[T]his study has been widely cited, notwithstanding its dubious methodology.” Under the terms of his employment contract, his “[p]erformance-based stock options shall not vest until December 31, 2025.” The Latin term sic, meaning “so” or “thus,” is used to indicate an error or confirm an unusual usage in the original material.
Quite simply, do not use bracketed material in a way that twists the author’s meaning.
There are a few different types of symbols that can technically be considered brackets.
If we remove the entire parenthesis from (1) above, we thus get the acceptable and understandable (2): In this particular case, (2), we get an acceptable result if we just remove the parentheses (i.e. However, in other cases, for instance in (3), the result of just removing the symbols would be strange, ungrammatical, or even incomprehensible.
Finally, something must be said about angle brackets, Such parenthetical information, which can be of different types, is not necessary in order to understand the text, and a sentence that contains parenthetical information must be complete and understandable even if the parenthetical information is removed (this does not mean, by the way, that the sentence must make sense if only the actual parentheses are removed).
For example, if the original quotation is “She never called back,” do not change it to “[Lucy] never called back.” Instead write: “She [Lucy] never called back.” (Note: Many newspapers ignore this rule.
In professional and academic writing, it is better to follow it.) In many cases, brackets can be avoided by reframing the quotation.Let’s look at an example: Quotation with brackets used correctly around a clarifying word: “It [driving] imposes a heavy procedural workload on cognition that .  Quotation with parentheses incorrectly used in place of brackets: “It (driving) imposes a heavy procedural workload on cognition that . Let’s look at another example: Quotation with brackets used correctly around an explanatory insert: “[D]riving is not as automatic as one might think; in fact, it imposes a heavy procedural workload [visual and motor demands] on cognition that . Quotation with parentheses incorrectly used in place of brackets: “[D]riving is not as automatic as one might think; in fact, it imposes a heavy procedural workload (visual and motor demands) on cognition that . Let’s look at an example: Original direct quotation beginning with an upper case letter: “The heavy cognitive workload of driving suggests that any secondary task has the potential to affect driver behavior” (Salvucci and Taatgen 108).Integrated quotation with brackets used correctly to indicate a change in letter case: Salvucci and Taatgen propose that “[t]he heavy cognitive workload of driving suggests that any secondary task has the potential to affect driver behavior” (108).Parentheses are sometimes used to enclose examples of what the main text is discussing.Here, too, we can remove the whole parenthesis without causing ungrammaticality or serious comprehension difficulties, but the examples within parentheses are often very helpful to the reader.Note: Brackets are placed around the lower-case letter‘t’ to indicate that the letter case has been changed.The quotation is introduced by a signal phrase, which makes the quote an integral part of the writer’s sentence; as a result of this syntactical change, the upper case ‘T’ in the original is changed to a lower case letter.Note that sic, as a foreign term, should be italicized, but the brackets containing it should not.What punctuation should be used when words are inserted or altered in a direct quotation?Parentheses are also used to enclose cross-references of the type found in (8): For more detailed information on how parentheses should be used in a particular reference system, please see the AWELU section on references and/or the reference guide or style manual that you have received from your teacher, supervisor, department, editor, or publisher.Finally, please note that it is common practice not to capitalise the first letter of a sentence within parenthesis, or use a full stop at the end, when this parenthesis is inserted inside (or at the very end) of another orthographic sentence (see definition of 'orthographic sentence' below), as in (9).