title: Why is only ) a special character and not } or ]?
body: <p>I'm reading <a href="https://rads.stackoverflow.com/amzn/click/com/1411677609" rel="nofollow noreferrer" rel="nofollow noreferrer">Jan Goyvaerts' "<em>Regular Expressions: The Complete Tutorial and Reference</em>"</a> to touch up on my Regex.</p>
  
  <p>In the second chapter, Jan has a section on "special characters:"</p>
  
  <blockquote>
    <h3>Special Characters</h3>
    
    <p>Because we want to do more than simply search for literal pieces of text, we need to reserve certain characters for special use. In the regex flavors discussed in this tutorial, there are 12 characters with special meanings: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, <strong>the opening parenthesis (, the closing parenthesis ), the opening square bracket [, and the opening curly brace {</strong>, These special characters are often called “metacharacters”. Most of them are errors when used alone.</p>
    
    <p><sup>(emphasis mine)</sup></p>
  </blockquote>
  
  <p>I understand that only open square bracket and open curly brace are special since a close brace or bracket is clearly a literal if there's no preceding open. <strong>However, why does Jan specify that close parenthesis <em>is</em> a special character if the other two close's aren't?</strong></p>