1. job requirements: airport cleaning needs to fill in forms or documents in the work, and these forms or documents need to be signed for confirmation. In this case, you will sign on blank A4 paper, and then copy these signatures to the form or document that needs to be signed.

2. Security considerations: airport cleaning requires signature on blank A4 paper to ensure that the signature will not be used for illegal purposes. You need to sign on blank paper, and then give these signatures to the employer to prove that the document or form has been signed.