Passport notarization refers to the authentication and identification of the information on the passport to prove the authenticity and validity of the passport. Passport notarization is usually used in the following situations: 1. Study abroad: When applying for study abroad or exchange programs, you need to provide a notarized passport to prove your personal identity and nationality. 2. Immigration application: When applying for immigration or permanent residence, you need to provide a notarized passport as proof of identity and nationality. 3. Employment application: When working in some countries, you may need to provide a notarized passport as proof of identity and nationality. 4. Marriage registration: When getting married in some countries, you need to provide a notarized passport as proof of identity and nationality. 5. Legal proceedings: When it comes to international legal disputes or cases, a notarized passport can be submitted as evidence to the relevant court. It should be noted that the requirements for passport notarization may vary from country to country, and the specific situation needs to be determined according to local laws and regulations.