How do ball mark inspections work on clay courts?

Ball mark inspection procedures (2026 ITF Rules of Tennis, Appendix VII):

1. Ball marks can be inspected only on clay courts.
2. A player's request is allowed only if the chair umpire can't determine the call with certainty from the chair, and only on a point-ending shot or when the player stops play during a rally (a return is allowed, then they must stop).
3. The chair umpire goes down and inspects the mark personally. A line umpire can help find it, but the chair umpire inspects it.
4. If the mark can't be found or is unreadable, the original call or overrule stands.
5. Once the chair umpire has ruled on a mark, the decision is final and can't be appealed.
6. Don't announce the score too quickly on clay unless certain; wait if an inspection may be needed.
7. In doubles, the appeal must stop play; a wrong or late appeal may be treated as a deliberate hindrance.
8. A player who erases the mark before the final decision concedes the call.
9. A player who crosses the net to check a mark is subject to the Unsportsmanlike Conduct provision of the Code of Conduct.