I also hold a number of vendor-specific certifications, which are ackhowledgements issued by companies to certify your proficiency level with their software or platform.
I currently hold these acknowledgements with cPanel, Mirantis (for OpenStack), and Nimble.
Linux - Redhat/CentOS, Debian/Ubuntu, cPanel, Plesk
Virtuozzo, OpenVZ, KVM, Xen, VMWare, Openstack, Cloud Services (AWS, Google, Most all cloud providers such as Digital Ocean, Rackspace, Vultr, etc)
Wordpress, CloudLinux, ModSec, CSF/APF/iptables, BIND, MySQL/MariaDB, Red5, Apache, Nginx, LiteSpeed, RoR
Nagios, Icinga, Cacti, Puppet, Git, GoCD, Duplicity, Restic
Bash, PHP, Python, HTML
PCI DSS, HIPAA, CSA, ISO 27001