After the document is uploaded, a thorough check of the validity of the signature and the level of the certificate used is performed. It is required that everything complies with the requirements that have been set for the signature. The external signature does not base the verification on the information in the certificate itself, but uses actual data from the issuing CA. An important part of this is the validation report, which provides the basis for an unambiguous decision on the correctness of the signature. If the signature does not meet the requirements, it is rejected.