I was working with a teammate importing certificates into a java keystore and I noticed our intermediate certificate had the ".L1K" notation, was then about to import into our Java application's keystore and saw there was another 'entrustl1k' certificate in the same keystore. So I wanted to find out what that means.
I found some information on Entrust's site here: https://www.entrustdatacard.com/pages/root-certificates-download
that it might indicate it's a 'Non Extended Validation Certificate here:
Entrust Certificate Authority ‐ L1K (Non‐EV SSL)'
However just beneath that line there was another "Non-EV SSL" cert download link with the 'L1M' notation.
"Entrust Certificate Authority ‐ L1M (EV SSL)"
Best Answer
It's simply the name of the certificate authority. They could just as well have been called "Entrust Certificate Authority - Foo (Non-EV SSL)" and "Entrust Certificate Authority - Bar (EV SSL)".
I'd guess that L1 stands for "level 1", and they then add on a letter to differentiate between their CAs. But for anyone outside of Entrust, it's just a name.