-/* Pipe a text file through 'tr "[a-z]" "[A-Z]"', which converts ASCII
- characters from lower case to upper case. */
+/* Pipe a text file through 'LC_ALL=C tr "[a-z]" "[A-Z]"', or equivalently,
+ 'tr "abcdefghijklmnopqrstuvwxyz" "ABCDEFGHIJKLMNOPQRSTUVWXYZ"', which
+ converts ASCII characters from lower case to upper case. */