More specific provisions:
Art. 6 II: "Member States may maintain or introduce more specific provisions [...] with regard to processing for compliance with points (c) and (e) of paragraph 1 by determining more precisely specific requirements [...] including for other specific processing situations as provided for in Chapter IX." ► Art. 88 is in Chapter IX.
More specific rules:
Art. 88 I: "Member States may, by law or by collective agreements, provide for more specific rules to ensure the protection of the rights and freedoms in respect of the processing of employees’ personal data in the employment context, in particular for the purposes of the recruitment, the performance of the contract of employment, including discharge of obligations laid down by law or by collective agreements, management, planning and organisation of work, equality and diversity in the workplace, health and safety at work, protection of employer’s or customer’s property and for the purposes of the exercise and enjoyment, on an individual or collective basis, of rights and benefits related to employment, and for the purpose of the termination of the employment relationship."