One of the options you can configure when adding, or editing, questions are the answer requirements.
Answer not required
This means that the shopper may submit the shop without answering the question.
A skipped question will score 0/X points, if the question has a point value assigned.
Answer always required
This option means that the selected the shopper must answer the question before submitting the shop.
If the question is not answered, an "Oops" message will be displayed.
Required if answer to ID#
This is a conditional response, and the question is only required if a specific response is provided to the specified question.
In this example, the question is being set as required when the answer to the question with the ID 141 is "Poor".
The shopper is now required to fill out the follow-up question when the previous question is answered "Poor". No other answer selection will cause the follow-up question to be required.
Conditionally required questions can also be used for making entire sections of a form active or inactive, depending on the circumstances of the shop. For example, some locations in a restaurant chain may have a bar, while others don’t, so all bar questions can be made conditionally required.
If a question is set to be conditionally required, the opposite will be true if the condition is not met. The question will be required not to have an answer unless the condition is met. This would apply in circumstances if the answer is filled by other means, such as Rulez, and would produce an "oops" on submitting the shop.
Keep in mind that, in Sassie terms, there is a difference between 'not required' and 'unrequired'.
'Not required' means that the question can be answered by the shopper, but is not required to be answered for them to submit the shop.
'Unrequired' means that a question cannot be answered based on conditional requirements.
For an example:
Question ID 31 is set to be required only when Question ID 21 is answered "Yes".
The shopper answers Question 21 with "No".
This makes the Question ID 31 'unrequired', and not being able to be answered by the shopper.
This 'unrequired' scenario is what the Skip Unrequired setting in the Survey Settings is referring to!