The Commission accepts the majority of the Parliament's amendments since it states that most of them improve the clarity and legal certainty of the text. In particular, the directive sets out minimum standards, and Member States may introduce higher standards of protection. It clarifies the circumstances under which a Member State may provide for a difference in treatment on the basis of sex, specifiying that this should only be when the aim is legitimate, and is within the confines of the principles of proportionality. With regard to maternity leave, the document makes clear that after such leave, women should also benefit from any improvement in working conditions to which they would be entitled during their absence. Protection against victimisation is extended not only to employees but also to trade union delegates supporting them and also to witnesses. The Member States are to submit reports every two years on positive action measures, instead of every year as proposed by the Parliament. Member States are to ensure dialogue with NGO's and to encourage employers to take all measures necessary to promote equality and to prepare annual equality reports, on the basis of which they may be required to improve the situation.�