I<inside> character classes, the [] are part of the construct, for
example: /[012[:alpha:]345]/. Note that [= =] and [. .] are not
currently implemented; they are simply placeholders for future
-extensions.
+extensions and will cause fatal errors.
=item Character class syntax [. .] is reserved for future extensions
-(W regexp) Within regular expression character classes ([]) the syntax
+(F regexp) Within regular expression character classes ([]) the syntax
beginning with "[." and ending with ".]" is reserved for future
-extensions. If you need to represent those character sequences inside a
-regular expression character class, just quote the square brackets with
-the backslash: "\[." and ".\]".
+extensions. If you need to represent those character sequences inside
+a regular expression character class, just quote the square brackets
+with the backslash: "\[." and ".\]".
=item Character class syntax [= =] is reserved for future extensions
-(W regexp) Within regular expression character classes ([]) the syntax
+(F) Within regular expression character classes ([]) the syntax
beginning with "[=" and ending with "=]" is reserved for future
-extensions. If you need to represent those character sequences inside a
-regular expression character class, just quote the square brackets with
-the backslash: "\[=" and "=\]".
+extensions. If you need to represent those character sequences inside
+a regular expression character class, just quote the square brackets
+with the backslash: "\[=" and "=\]".
=item Character class [:%s:] unknown