What does the bracket indicate in GCSE results?

In GCSE results, a bracket indicates a grade boundary. It shows the lowest raw mark needed to achieve a particular grade. For example, a result might be shown as a 7 (65-70), meaning a raw mark between 65 and 70 inclusive was needed to get a grade 7. Different exam boards may use brackets slightly differently, but the fundamental purpose remains the same: to clarify the mark range for each grade.