Index: /branches/czw_branch/20170908/Ohana/src/libohana/src/isolate_elements.c
===================================================================
--- /branches/czw_branch/20170908/Ohana/src/libohana/src/isolate_elements.c	(revision 40204)
+++ /branches/czw_branch/20170908/Ohana/src/libohana/src/isolate_elements.c	(revision 40205)
@@ -171,5 +171,5 @@
   // order matches convert_to_RPN.c
   if (!strncmp (c, "?",  1)) return (TRUE);
-  if (!strncmp (c, ":",  1)) return (TRUE);
+  // if (!strncmp (c, ":",  1)) return (TRUE);
 
   if (!strncmp (c, "^",  1)) return (TRUE);
Index: /branches/czw_branch/20170908/Ohana/src/opihi/lib.shell/evaluate_stack.c
===================================================================
--- /branches/czw_branch/20170908/Ohana/src/opihi/lib.shell/evaluate_stack.c	(revision 40204)
+++ /branches/czw_branch/20170908/Ohana/src/opihi/lib.shell/evaluate_stack.c	(revision 40205)
@@ -188,4 +188,8 @@
 	  snprintf (line, 512, "syntax error: invalid operand for binary operation: %s or %s\n", stack[i-1].name, stack[i-2].name);
 	  push_error (line);
+	  if (strchr(stack[i-1].name, ':') || strchr(stack[i-2].name, ':')) {
+	    snprintf (line, 512, "syntax error: invalid operand for binary operation: %s or %s\n(Note that the : in a trinary operation must be protected by spaces)\n", stack[i-1].name, stack[i-2].name);
+	    push_error (line);
+	  }
 	  clear_stack (&tmp_stack);
 	  return (FALSE);