The Client Certificates tab contains three types of certificates:
Almost always it has premium certificate preferred. It The preferred ones should almost always be the Premium Certificates. A premium certificate is useful for personal
Client Authentication
Document Signing
Email Encryption
Email Signing
Use Don't use the Digital Signature Plus NEVER certificate certificate; it is just a variant of limited Premium.
Email Security Plus offers the possibility to store have your private key by stored by DigiCert (escrow). You do therefore not waiting for a revelation of Mr. Snowden: You already know in advance that you are secret keys in an American organization. That might be in strange cases still useful, for example to decrypt a digital legacy from the organization.