CRPD/C/GC/2 which must be adopted in consultation with organizations of persons with disabilities, and they need to be specified for service-providers, builders and other relevant stakeholders. Accessibility standards must be broad and standardized. In the case of individuals who have rare impairments that were not taken into account when the accessibility standards were developed or who do not use the modes, methods or means offered to achieve accessibility (not reading Braille, for example), even the application of accessibility standards may not be sufficient to ensure them access. In such cases, reasonable accommodation may apply. In accordance with the Convention, States parties are not allowed to use austerity measures as an excuse to avoid ensuring gradual accessibility for persons with disabilities. The obligation to implement accessibility is unconditional, i.e. the entity obliged to provide accessibility may not excuse the omission to do so by referring to the burden of providing access for persons with disabilities. The duty of reasonable accommodation, contrarily, exists only if implementation constitutes no undue burden on the entity. 26. The duty to provide reasonable accommodation is an ex nunc duty, which means that it is enforceable from the moment an individual with an impairment needs it in a given situation, for example, workplace or school, in order to enjoy her or his rights on an equal basis in a particular context. Here, accessibility standards can be an indicator, but may not be taken as prescriptive. Reasonable accommodation can be used as a means of ensuring accessibility for an individual with a disability in a particular situation. Reasonable accommodation seeks to achieve individual justice in the sense that non-discrimination or equality is assured, taking the dignity, autonomy and choices of the individual into account. Thus, a person with a rare impairment might ask for accommodation that falls outside the scope of any accessibility standard. III. Obligations of States parties 27. Even though ensuring access to the physical environment, transportation, information and communication, and services open to the public is often a precondition for the effective enjoyment of various civil and political rights by persons with disabilities, States parties can ensure that access is achieved through gradual implementation when necessary as well as through the use of international cooperation. An analysis of the situation to identify the obstacles and barriers that need to be removed can be carried out in an efficient manner and within a short- to mid-term framework. Barriers should be removed in a continuous and systematic way, gradually yet steadily. 28. States parties are obliged to adopt, promulgate and monitor national accessibility standards. If no relevant legislation is in place, adopting a suitable legal framework is the first step. States parties should undertake a comprehensive review of the laws on accessibility in order to identify, monitor and address gaps in legislation and implementation. Disability laws often fail to include ICT in their definition of accessibility, and disability rights laws concerned with non-discriminatory access in areas such as procurement, employment and education often fail to include access to ICT and the many goods and services central to modern society that are offered through ICT. It is important that the review and adoption of these laws and regulations are carried out in close consultation with persons with disabilities and their representative organizations (art. 4, para. 3), as well as all other relevant stakeholders, including members of the academic community and expert associations of architects, urban planners, engineers and designers. Legislation should incorporate and be based on the principle of universal design, as required by the Convention (art. 4, para. 1 (f)). It should provide for the mandatory application of accessibility standards and for sanctions, including fines, for those who fail to apply them. 8