+The "-o" (oldstyle) option reverts the behavior.
+
+There is a set of standard one-letter command aliases conventional in modern
+text adventure games; 'l' and 'x'; for 'look' (or 'examine'), 'z' to do nothing
+for a turn, 'i' for 'inventory', 'g' for 'get', and 'd' for 'drop'. The 'd'
+alias collides with 'd' for 'down', but the others have been implemented.
+The "-o" (oldstyle) option disables them.
+
+Unrecognized words are no longer truncated to 5 characters and
+uppercased when they are echoed. The "-o" (oldstyle) option restores
+this behavior.
+
+Typing a numeric literal to the command prompt no longer triggers a
+fatal error. This change is reverted by the oldstyle option.