+#
+# Message strings may include certain special character sequences to
+# denote that the program must provide parameters to insert into a
+# message when the message is printed. These sequences are:
+# %S = The letter 'S' or nothing (if a given value is exactly 1)
+# %W = A word (up to 10 characters)
+# %L = A word mapped to lower-case letters
+# %U = A word mapped to upper-case letters
+# %C = A word mapped to lower-case, first letter capitalised
+# %T = Several words of text, ending with a word of -1
+# %1 = A 1-digit number
+# %2 = A 2-digit number
+# ...
+# %9 = A 9-digit number
+# %B = Variable number of blanks
+# %! = The entire message should be suppressed