Glossary
Required vs optional fields
Whether an answer must be provided before the form can submit.
A required field blocks submission until it is answered; an optional one does not. Every field you mark required raises data completeness but also raises friction and form abandonment, so the decision is an explicit trade between coverage and conversion.
Mark a field required only if a submission is genuinely unusable without it. "Nice to have" fields should be optional or removed entirely — an optional field you never analyse is pure friction with no payoff. Audit your export periodically and delete fields nobody reads.
Communicate requirement clearly and consistently. Marking required fields (rather than optional ones) is conventional when most fields are optional, and vice versa; whichever you choose, the indicator must be programmatically associated with the field for screen-reader users, not conveyed by colour alone — see form accessibility.