Hour claim settings is the fifth and last section of an opportunity's Schedule settings. An hour claim is the person telling you what they worked, rather than a check-in recording it, so this section decides who may claim, what happens to a claim once it arrives, and what you collect alongside it.
It matters most for work that happens away from a shift: someone who helped out without being on the schedule, or who stayed two hours longer than their reservation.

While creating an opportunity, on the Customize step under Schedule. After it is published, go to Opportunities > open the opportunity > Schedule tab, then open the Hour claim settings card.
Several settings below turn on this distinction, so it is worth stating once:
A reservation-level claim is attached to a past shift the person was reserved for.
An opportunity-level claim has no reservation behind it. The person is claiming hours on the opportunity itself, which is sometimes called retroactive scheduling.
Decides which of those two kinds of claim a user can make. Three options:
Both. Users can claim hours for past reservations and can also generate an opportunity-level claim with no past reservation. The default.
Reservations only. Users can only claim hours tied to past reservations in their schedule, so they must have been assigned to a shift.
Neither. Users cannot claim hours at the reservation level or the opportunity level.
Choose Reservations only when every hour should trace back to a shift you scheduled. Choose Neither when hours are yours to log and not theirs to submit.
By default every hour claim waits for an administrator. Three options:
All hour claims must be approved by an admin. The default.
All hour claims are auto-approved.
Only claims tied to a shift the attendee was reserved for are auto-approved.
The third option is the useful middle ground. A claim against a shift you scheduled is largely self-verifying, so it goes straight through, while a claim that appears out of nowhere still lands in your queue.
Once a user already has hours logged against a shift reservation, this lets them claim more on top. Turn it on for work that regularly runs long, and leave it off if the scheduled hours are the hours.
Requires a specific form to be submitted with the claim. It applies to the opportunity-level claim flow, where the user was not already reserved for a shift.
That scope is the point of the setting. An unscheduled claim is the one you know least about, so this is where asking a few questions earns its keep: what they did, where, and who asked them to.

Controls whether users are asked to add a note when claiming hours, and whether the note is required. Three states:
Disabled. No note is requested.
Prompt for note. The note field appears but can be left blank.
Require adding a note. A note must be entered before the claim can be submitted.
A note is the lightweight version of setting 4. Where a form is more than you need, a required note still gives you one line of context on every claim.
Hour claims come in two kinds: attached to a past reservation, or made on the opportunity with no reservation behind them.
Setting 1 decides which kinds users can make, including turning claims off entirely.
Auto-approval can be off, on for everything, or on only for claims tied to a real reservation.
Additional hours on top of an already-logged shift are a separate switch.
The form submission policy applies only to opportunity-level claims, not to reservation-level ones.
The note policy is the lighter option, and it can be optional or required.