Proviso

Proviso means a conditional provision to an agreement. It may refer to
 * Proviso Township, Cook County, Illinois, United States
 * Proviso Township High Schools District 209 that comprises
 * Proviso East High School
 * Proviso West High School
 * Proviso Mathematics and Science Academy
 * Wilmot Proviso, an American law to ban slavery in annexed territory from Mexico proposed by David Wilmot in the 1840s
 * Lockean proviso, a feature of John Locke's labour theory of property