Hukou notarization refers to notarizing an individual's Hukou to prove the authenticity and validity of the household registration information. It is usually used in the following situations: 1. Studying abroad: Many countries and schools require international students to provide Hukou notarization as one of the application materials to prove their identity and household registration information. 2. Immigration application: In some immigration countries, applicants need to provide Hukou notarization to prove their family relationship, marital status, children and other information. 3. Employment application: Some employers or institutions may require job seekers to provide Hukou notarization to verify their personal information and identity. 4. Marriage registration: In some countries or regions, if one of the parties to the marriage is a foreigner, it may be necessary to provide Hukou notarization as one of the documents required for marriage registration. 5. Property inheritance: In the process of property inheritance, the court or relevant institutions may require the heir to provide Hukou notarization to prove his or her relationship with the heir. It should be noted that the specific purpose and effectiveness of the use of Hukou notarization should be determined according to local laws and regulations, and different countries and regions may have different requirements and procedures.