1. Education level: You usually need a certificate with at least a bachelor's degree or equivalent.
2. Professional background: Candidates with library science or related professional knowledge or related work experience are preferred.
3. Cataloging knowledge: understand the book cataloging standards and be familiar with the use of related software and tools, such as Marc editor.
4. Information literacy: Good computer operation and office automation skills, and efficient use of computer and electronic resources.
5. Language ability: proficient in the required languages, such as English, Spanish, Chinese, etc.
6. Communication skills: Have good communication skills, be familiar with and meet the needs of readers.
7. Service attitude: provide quality service through proactive work attitude and good service awareness.
The above are just some basic conditions, and the actual requirements and conditions may be adjusted according to the job level, job content and country/region. If you want to work in a specific library, I suggest you check the specific recruitment positions and requirements of the library.