The types of data contained within an X509 certificate will be arranged in a specific manner. There are set locations where data is stored within the certificate, which will be the same regardless of the organization which created the certificate. For example, you will find the creator’s name, creation date and validity period in the same place in each certificate following this standard.
Some Organizations May Use Customized Versions of X509 Certificates
Sometimes you may see a decimal and number behind X509. All this may imply is that the organization has made some type of modification to the certificate to create a new version. For instance, they may decide to add optional information, which is not necessary, but included, to distinguish their certificates from others. By adding the decimal and a number to the certificate, they can tell their customized certificates from other certificates.