Note 2 — BRACKETS (or THE PARENTHESIS.[2])
Reading edition
It seems better to use the term "brackets" both for the curved and for the square brackets. "Parenthesis" can then be kept to its proper use, as the name for the words themselves which form the break in the sentence. We may note that in like manner the terms "comma," "colon," "semicolon," originally signified divisions of a sentence, not marks denoting the divisions. "Period" meant a complete sentence; and it still retains the meaning, somewhat specialized.