When the allowed values for one field are dependent on the value of another field, you can use multiple tables to validate the field.
In this situation, FORMS can select a validation table to use depending on the value of another field.
The table name of the validation table depends on another field’s value.
An extra table is used to determine the correct validation table. This extra table is called a connection table. It contains possible values for the via field (the one that steers which values are valid for the dependent field) as well as the names of the validation tables to use for the dependent field.
For example, trousers may have one set of valid sizes, whereas shirts have other valid sizes. In this case, the validity of the value in Size (the dependent field) is dependent on the value in Product (the via field)
FORMS looks up the value of Product (the via field) in the connection table, to get the name of the validation table to use for Size (the dependent field).