The electronic seal contains data of a legal entity such as:  CN – the entity's common name (it does not have to be an official name); Organization identifier - most often this is a tax identification number (NIP), a registration number of the national economic register (KRS) or an ETSI-compliant regional identifier notified in the European Union countries. International two-letter country abbreviation (for Poland it is PL); Information about where the entity was registered; The official name of the subscriber (within the meaning of the Commercial Companies Code, e.g. the company or the name of the entrepreneur).