This type takes on one of the two following values:
- 1,1 : it means that for each line in the table of origin, only one line in the linked table is read (this line is defined by the key expression).
- 1,N: in this case, several lines in the linked tables can be read. They are defined by the key expression, that can be incomplete if it is divided into several parts (those lines whose entered key elements correspond to the given value are run through).