reg --strict
<<<
2007/02/02 * Foo
    Expenses:Food                         $10.00
    Assets:Cash

2007/02/03 Bar
    * Expenses:Food                       $20.00
    Assets:Cash

2007/02/02 Baz
    Expenses:Foodx                        $30.00
    Assets:Cash
>>>1
07-Feb-02 Foo                   Expenses:Food                $10.00       $10.00
                                Assets:Cash                 $-10.00            0
07-Feb-02 Baz                   Expenses:Foodx               $30.00       $30.00
                                Assets:Cash                 $-30.00            0
07-Feb-03 Bar                   Expenses:Food                $20.00       $20.00
                                Assets:Cash                 $-20.00            0
>>>2
Warning: "$FILE", line 10: Unknown account 'Expenses:Foodx'
=== 0