Which scorelines are valid in a ladder match?

Whatever the format allows, and nothing else. A best-of-three match cannot end 8-6. A pro set cannot end 6-4 6-2. A 7-6 set requires a tiebreak reaching at least seven points won by two, so 9-7 is valid and 7-6 as a bare game score is not. Publishing the accepted list is a five-minute job that prevents a season of ambiguous entries. Every accepted scoreline.