Field modification rule against Position Object which references a UDT (use case 42)

Hello,

I have created a Field Modification rule under the Position object and the Assignment Category field. The use case is 42 and it has been approved. The purpose of the rule is to set the value of a flexfield, depending on what Assignment Category is selected. The rule references a UDT to do this. We are able to hard-code the value mapping into the autocomplete rule itself, but it suits our business better to use a UDT.

E.g. if you select "Assignment Category 1" then the flexfield should be set to "Value 1".
if you select "Assignment Category 2" then the flexfield should be set to "Value 2".