When you try to add a Skill to the Primary Skill field when it is already in the Secondary Skill field or vice versa, the option will be grayed out and you will see a warning advising the selected value is already in the other Skill field.
When you try to add a Skill to the Primary Skill field when it is already in the Secondary Skill field or vice versa, the option will be grayed out and you will see a warning advising the selected value is already in the other Skill field.