p4raw-id: //depot/perl@32376
Octal escapes consist of a backslash followed by two or three octal digits
matching the code point of the character you want to use. This allows for
-522 characters (C<\00> up to C<\777>) that can be expressed this way.
+512 characters (C<\00> up to C<\777>) that can be expressed this way.
Enough in pre-Unicode days, but most Unicode characters cannot be escaped
this way.