Unless more are found, all braces have been fixed

I don't know, however, about closing the issue #2114. Several problems

* We need a generic name that includes parentheses/braces/brackets
* Do we need/want the test? It might include some verbosity
* Sometimes parentheses (plural) is spelled parenthesis (singular).

Author: JJ

doc/Language/regexes.pod6

@@ -1170,7 +1170,8 @@ Note that neither the colon C<:> nor balancing delimiters such as C<{}> or
 C<()> can be substitution delimiters. Colons clash with adverbs such as
 C<s:i/Foo/bar/> and the other delimiters are used for other purposes.
 
-If you use balancing brackets, the substitution works like this instead:
+If you use balancing brackets/braces/parentheses, the substitution works like
+this instead:
 
     s[replace] = 'with';
 
@@ -1610,7 +1611,7 @@ Whereas these two are not:
     my $rx3 = rx/a :i b/;   # matches only the b case insensitively
     my $rx4 = rx/:i a b/;   # matches completely case insensitively
 
-Brackets and parentheses limit the scope of an adverb:
+Square brackets and parentheses limit the scope of an adverb:
 
     / (:i a b) c /;         # matches 'ABc' but not 'ABC'
     / [:i a b] c /;         # matches 'ABc' but not 'ABC'
@@ -1958,10 +1959,10 @@ to the more readable
     }
 
 As a rule of thumb, use whitespace around atoms and inside groups; put
-quantifiers directly after the atom; and vertically
-align opening and closing brackets and parentheses.
+quantifiers directly after the atom; and vertically align opening and closing
+square brackets and parentheses.
 
-When you use a list of alternations inside a parenthesis or brackets, align
+When you use a list of alternations inside parentheses or square brackets, align
 the vertical bars:
 
     my regex example {
@@ -2036,8 +2037,8 @@ restrictive. Somebody might write C<[two words]>, or use dashes, etc.
 Instead of asking what's allowed on the inside, it might be worth asking
 instead: I<what's not allowed?>
 
-Clearly, closing brackets are not allowed, because C<[a]b]> would be
-ambiguous. By the same argument, opening brackets should be forbidden.
+Clearly, closing square brackets are not allowed, because C<[a]b]> would be
+ambiguous. By the same argument, opening square brackets should be forbidden.
 This leaves us with
 
     token header { '[' <-[ \[\] ]>+ ']' }