Bringing Your Own CA

The Web zone options (--web-ca-*) behave the same on 1.5 and 1.6. The Secure Boot zone is where the lines part: 1.6’s --secureboot-ca-cert is a genuine CA replacement and has no 1.5 equivalent — 1.5 can only accept a flat leaf certificate.

Which version am I on?

Check FOG Configuration → FOG Settings → General → FOG_VERSION in the web UI, or the version string printed at the top of installfog.sh.