The cornerstone of the prohibition of discrimination is Article 91 of the Latvian Constitution providing, inter alia, that human rights shall be observed without discrimination of any kind. Thus, the Constitution outlaws all discrimination, but does not expressly state the grounds on which discrimination is prohibited. The Constitution is regarded as having direct effect, that is, it directly binds all public bodies, but it does not have horizontal effect. This means that while discrimination is illegal in the public sector even without any further laws, which are thus only needed to provide for sanctions and the enforcement of the principle of non-discrimination, in the private sector the introduction of special laws to outlaw discrimination is essential. The same applies to international treaties: the treaties binding on Latvia only bind the public bodies.