This field has as its Object to supply the values to be assigned to each component to the key for the link selected above. The number of components in the link expression must correspond to the number of components in the key. It is not possible to only use the first or second part of a key. All the specified key components must have a corresponding value in the link expression.
Syntax rules:
1/Each key component must be separated by a semi-colon.
2 / Each alphanumeric value must be enclosed within speech marks.
3 / Although not mandatory, but in order to avoid all risks of conflict in variable names, it is strongly recommended to enter each field name before by its standard class abbreviation.