The present document specifies CAdES digital signatures. CAdES signatures are built on CMS signatures [i.8], by incorporation of signed and unsigned attributes, which fulfil certain common requirements (such as the long term validity of digital signatures, for instance) in a number of use cases. The present document specifies a number of CAdES signature levels addressing incremental requirements to maintain the validity of the signatures over the long term, in a way that a certain level always addresses all the requirements addressed at levels that are below it. These CAdES extended signatures a higher degree of optionality than the CAdES baseline signatures specified in ETSI EN 319 122-1 . The present document aims at supporting digital signatures in different regulatory frameworks. NOTE: Specifically but not exclusively, CAdES digital signatures specified in the present document aim at supporting electronic signatures, advanced electronic signatures, qualified electronic signatures, electronic seals, advanced electronic seals, and qualified electronic seals as per Regulation (EU) No 910/2014 [i.7].