Extra fields cascading drop-down list

In the Suppliers modules there are additional attributes for invoices
I am trying to make a selection list in function of another.
I will generate a list of selections called “Rubro”
And now I want to put another list of selection that is filtered by the list “Rubro”.

The help appears:

1, value | parent_list_code: parent_key
2, value | parent_list_code: parent_key

In my case it would

List of selection " Rubro"

  1. Tax
  2. Fixed Cost

The second list would

1, VAT | Taxes: Rubro
2, IB | Taxes: Rubro
3, Bookstore | Fixed Costs: Rubro
4, Light | Fixed Costs: Rubro

But this does not work.

Anyone know what is the character “|” which separate the list from the filter?
Or I am making other mistake,?

Pièces jointes :

see
for the answer