Under administrative law, the doctrine of 'legitimate expectation' protects: 

The doctrine of legitimate expectation protects a person's reasonable expectation of being treated in a certain way by a public authority, arising from the authority's past practice, regular conduct, representation, or promise, even where the person cannot point to a substantive legal right to such treatment. It is a procedural and sometimes substantive safeguard-at minimum, it requires the authority to give a hearing before departing from the expectation, and in some cases, it may prevent the authority from acting inconsistently with the expectation. The Supreme Court in Food Corporation of India v. Kamdhenu Cattle Feed Industries (1993) recognised this doctrine but cautioned that it cannot override statutory provisions or public interest. In Navjyoti Co-op. Group Housing Society v. Union of India (1992), the Court observed that it can give rise to judicial review if the expectation is frustrated arbitrarily.