create index not in customer index

Hi,

I have to create the index "010" for table N1VKG in our development system as described in note 1874216.

If you want to create or change the delivered secondary indexes in advance, you must proceed as follows:

• Call transaction SE11.
• Enter N1VKG  in the "Database Table" input field and choose "Change".
• Click the "Indexes..." pushbutton.
• Click the "Create Index" pushbutton.
• Enter 010 in the "Index Identification" field.
• Click the "Continue (Enter)" pushbutton.
• In the #Short Description# field enter the text "Entry Date Only".
• Enter the following fields in this sequence in the "Field Name" column: MANDT, ERDAT
• Click the "Activate" pushbutton

But I cannot create the index "010" because "Index N1VKG-010 is not in the customer namespace".

How could I create this index?

Thanks