Persons, not FTE. Thresholds: staff meeting from 10, works council (OR) from 50 employees.
Explanation
The WOR counts "persons working in the enterprise" (Art. 1 paras. 2–3 WOR): employees with an employment contract, regardless of hours. Agency workers count after 15 months (Art. 1 para. 3 sub a). Count persons, not FTE.
For example: 63 employees → works council (OR) legally required (Art. 2 para. 1 WOR).