Article 4 Occupational requirements 1. Notwithstanding Article 2(1) and (2), Member States may provide that a difference of treatment which is based on a characteristic related to any of the grounds referred to in Article 1 shall not constitute discrimination where, by reason of the nature of the particular occupational activities concerned or of the context in which they are carried out, such a characteristic constitutes a genuine and determining occupational requirement, provided that the objective is legitimate and the requirement is proportionate. 2. Member States may maintain national legislation in force at the date of adoption of this Directive or provide for future legislation incorporating national practices existing at the date of adoption of this Directive pursuant to which, in the case of occupational activities within churches and other public or private organisations the ethos of which is based on religion or belief, a difference of treatment based on a person's religion or belief shall not constitute discrimination where, by reason of the nature of these activities or of the context in which they are carried out, a person's religion or belief constitute a genuine, legitimate and justified occupational requirement, having regard to the organisation's ethos. This difference of treatment shall be implemented taking account of Member States' constitutional provisions and principles, as well as the general principles of Community law, and should not justify discrimination on another ground. Provided that its provisions are otherwise complied with, this Directive shall thus not prejudice the right of churches and other public or private organisations, the ethos of which is based on religion or belief, acting in conformity with national constitutions and laws, to require individuals working for them to act in good faith and with loyalty to the organisation's ethos. Article 5 Reasonable accommodation for disabled persons In order to guarantee compliance with the principle of equal treatment in relation to persons with disabilities, reasonable accommodation shall be provided. This means that employers shall take appropriate measures, where needed in a particular case, to enable a person with a disability to have access to, participate in, or advance in employment, or to undergo training, unless such measures would impose a disproportionate burden on the employer. This burden shall not be disproportionate when it is sufficiently remedied by measures existing within the framework of the disability policy of the Member State concerned. Article 6 Justification of differences of treatment on grounds of age 1. Notwithstanding Article 2(2), Member States may provide that differences of treatment on grounds of age shall not constitute discrimination, if, within the context of national law, they are objectively and reasonably justified by a legitimate aim, including legitimate employment policy, labour market and vocational training objectives, and if the means of achieving that aim are appropriate and necessary. Such differences of treatment may include, among others: (a) the setting of special conditions on access to employment and vocational training, employment and occupation, including dismissal and remuneration conditions, for young people, older workers and persons with caring responsibilities in order to promote their vocational integration or ensure their protection; (b) the fixing of minimum conditions of age, professional experience or seniority in service for access to employment or to certain advantages linked to employment; (c) the fixing of a maximum age for recruitment which is based on the training requirements of the post in question or the need for a reasonable period of employment before retirement. 2. Notwithstanding Article 2(2), Member States may provide that the fixing for occupational social security schemes of ages for admission or entitlement to retirement or invalidity benefits, including the fixing under those schemes of different ages for employees or groups or categories of employees, and the use, in the context of such schemes, of age criteria in actuarial calculations, does not constitute discrimination on the grounds of age, provided this does not result in discrimination on the grounds of sex. Article 7 Positive action 1. With a view to ensuring full equality in practice, the principle of equal treatment shall not prevent any Member State from maintaining or adopting specific measures to prevent or compensate for disadvantages linked to any of the grounds referred to in Article 1.